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2 How to start
How to start a wireless ISP?
Read everything you can get your hands on and then check out the following links and read them in their entirety:
I want to start a wireless ISP (dslr thread) -this is the forum thread that I started when I got the bright idea to be a WISP
The WISP Directory
StartAWisp.com - name speaks for itself. An organized collection of various topics/posts related to many aspects of starting a WISP.
WISP FAQs - "This site is a collection of questions and answers that have been compiled and submitted by WISP's from around the world."
This is what I would call a great starting place to learn the basics as these are all the articles that I read that started me down the road to be a WISP!!!!
Note: Some of the above info is old or non-existent now. A good thread with relatively recent information can be found here, and is a good starting point:
»[Equipment] Starting a WISP
How to do a search on WISP-related info...
Many people here ask very general questions which could be easily answered in a simple search. One of my personal favorite search engines is Google
Here are a few tips to get the web page you're looking for faster:
If you're searching for something with two or more words, then use commas. For example, if I was searching for how to convert db to watts, then it would look like this: "dbm to watts."
You should also use multiple words. For example, searching for our free products
will return more relevant results then just products
. Placing those search terms in quotes will eliminate search engine returns for each individual word in the phrase.
To get some more tips for searching, I have include some links to a few good sites:Atomz Search TipsGoogle Help Central
How long will it take to make some money?
This question was asked in the WISP Forum and this is a summary of the responses.
Q: I have been doing the ground work toward starting a WISP. Now I am about down to crunch time. In other words, that point where I decide whether "to do or not to do."
I am looking at providing to areas that have no other high speed options. Very rural areas, total potential customers is around 3000. I have no doubt that technically I will be able to handle this. One of my goals with this will be to make a living at it and hopefully have a little more time with the family. I realize this requires a lot of work.
My question to you is, do you feel that I can make a living at this (say within 2 years) or will this just be something that takes even more time away from the family? Also, how many of you do this for a living versus a sideline to a full-time job?
A: Here are some of the answers:
"It will end up taking a lot more time away from the family - if you think otherwise you are kidding yourself."
"For a WISP to be your sole income, you need to quickly get to a point where you are generating enough revenue to pay yourself the salary you need to survive. That requires that you initially build enough infrastructure to quickly get that critical mass of customers to begin covering your MRC (which will include your salary). Depending on the wireless architecture you select, your geography, and lots of other factors, that could require a significant investment. If you can get to that same revenue stream incrementally over 2 years while maintaining another source of income, you can probably manage the transition. However, do some math and you'll see that the number of subscribers required to produce that much income is substantial and will be more than you can handle alone. If you can bring on a few partners in the same situation you are in, it's easier."
"This might be possible depending on how you approach the job. Price your services rationally, and read a LOT about equipment before you buy it."
Q: More time with the family?
"No, don't look for this for at least a couple of years. There's so much more than merely installing antennas and buying a T1. The administration of a business is a full-time job in itself. You'll be doing at least three people's work: Executive, technician, and administrator. You'll be on the road a lot. You'll be climbing up on things... Join the mailing lists for WISPers and read the archives, especially the "war stories." The strongest list is WISP@part-15.org. You don't have to join Part-15 to join the list. The other list is email@example.com. As far as I know, the two lists and this forum are the main nexuses for members of the fixed wireless Internet industry. "
"When you first start out expect the unexpected. You will spend days if not weeks or months like I did trying to figure out this and that. If you use the right gear for your application things seem to become stable at some point. At least for me anyway. Once things become stable you will reach a bump in the road here and there. The last three months have been smooth for me. No problems to speak of. As far as financially only you can be the judge of that. You need to have a very good business plan and see if the numbers work. Just my 2 cents."
Q: One of my goals with this will be to make a living at it and hopefully have a little more time with the family.
"The only way you are going to see this happen is if the spouse is the admin, your 2 kids, or as many as you have, are the installers and you handle the marketing and sales. IMHO."
"To give you a brutally honest answer, I am a computer scientist (I mean a "for real" Computer Scientist with a degree). When I worked for the Navy, I was paid about 38k. When I worked for TRACOR, I was paid about 48k, when I worked for E-Systems I was paid about 90k... Today I am building a WISP, we are 2.5 years into the project, I make (before taxes) 14.4k... That is the down side. I work as essentially as a consultant, someone else owns the business and he cuts the pay checks. His check is SLIGHTLY SMALLER than mine... He is one hell of a good young man, with investors."
"The up side is that I go to work when I want. I leave work when I want and I get to play with the toys I want to play with."
"You will never get rich running an ISP (WISP), but you might make a nice family business of it. It will not be easy. Hell, it will NEVER be easy but if you want it you can do it."
"I've been building ISP's in Eastern Virginia for about eight years now. By that I mean that I have a habit of taking a young person in tow and showing them the ropes until they are able to fend for themselves."
Books for Beginners
Here are four books I've found to be really good at getting my skills up to speed to try and attempt this venture I've started.
•TCP/IP Network Administration by Craig Hunt. ISBN# 0-596-00297-1
•T1: A Survival Guide by Matthew Gast. ISBN# 0-596-00127-4
•Building Wireless Community Networks by Rob Flickenger. ISBN# 0-596-00204-1
•802.11 Wireless Networks by Matthew Gast. ISBN# 0-596-00183-5
All of these are published by O'Reilly
, and are available at better bookstores, or from Amazon
at better prices.
You'll also need a couple of books on whatever Operating System you choose to run, and a book or two on DNS, Mail Servers, Radius (if you run it), and Security.
I know there are more books out there than I could ever read in a lifetime, but these helped get me started.
So You Wanna Put Up A Tower?
Be prepared to face opposition, generally speaking people don't like towers. Tower selection:
Select a tower suitable for your proposed current needs, and also to accommodate upcoming desires. Perhaps in the future you will want to either add more equipment to your existing tower or rent space out to someone else. If your tower isn't capable to handling the increased load capacity you may be forced to erect a new tower and start this process over again. When calculating how much square feet of resistance will be on the tower don't forget to include crow's nests, top hats, or standoffs used for antenna placement in your estimations. Be sure your tower manufacture has an ICBO#, expect your development department to ask for this. Permitting process:
Your local development department will require that you obtain a building permit, and perhaps other permits for your new tower. Zoning
If your selected area is not commercially zoned you will need to complete a site approval application and pay a processing fee ($2000+/-). Your site approval will be subject to certain conditions such as improving driveway access and equipping the tower with an equipment shed, lighting, and signing a waiver allowing the development department to allow future tower developers to use your tower for their needs provided at a reasonable rent. If they find an existing suitable tower for your needs within a given area they will deny your request and require you use that existing tower. If not be prepared for the development department to survey neighbors and post public notices. Structural Calculations
The development department will want an engineer licensed in your state to review your selected tower and accompanying equipment and draw up a set of structural calculations for both the footings and wind speed. They will most likely require 2-4 copies of stamped, wet signature calculations ($3500+/-). Soil Sample
If the footings designed for the tower are rated for soil above your local area's threshold (around 1500 PSF) a core-type soil sample analysis will be required by a state licensed geotechnician ($3000+/-). If your footings are designed for 4000 PSF (like Trylon TSF Titan T-200) and your soil checks in at only 3000 PSF your structural engineer will need to re-draw the footings to accommodate that type of soil. It may be beneficial to determine your local threshold and have your structural engineer redraw the footings to fall below that limit at the same time he provides the wind-load calculations. This will avoid the need for a soil sample. Building Permit
The building permit itself will carry a filing fee and subject your project to new found taxes, inspections, hazmat inquiries, and a whole host of other headaches ($400+/-). FAA
The FAA will want you to file FAA Form 7460-1, Notice of Proposed Construction or Alteration. The development department may also require this. Encroachment permits
May be required if you are close to public access roads. Site preparation:
Your project area will need to clear of obstruction so a crane, backhoe, and other equipment can gain access. Tower unloading
Sometimes you will need equipment on your receiving end to unload the tower when it is shipped, ask your distributor/shipper for more information. Backhoe
To dig the hole will require a backhoe, estimate $150-300 for this. Tower erection
You will most like require a crane to assist you in this process, depending on your area and the crane company this can cost as little as $300 but usually more in the $6-700 range. Be sure to ask for references and experience with towers. Concrete
Each cubic yard of concrete will cost roughly $80-110. Reinforcement rod
Many tower footings call for grade 60 rebar, a pre-constructed cage will cost $150-500. Tower jockey
If you don't want to climb the tower yourself you will need to pay someone else. This will probably be required to detach the crane's equipment from the tower once put into place. Someone will also need to bolt the sections. Will also be required for aiming directional antennas, routing cable etc. Equipping your tower:
Once your tower is permitted and erected (I guarantee YOU won't be at this point) - your tower needs to be properly equipped. Paint
The FAA or development department may require you paint your tower for aircraft visibility purposes; this price will vary considerably. Lighting
The FAA or development department may require you light your tower for aircraft visibility purposes, this price will also vary depending on what type of lights and the quantity required ($700+/-). May require backup source of electricity. Safety
You might consider no-climb sides for your tower to reduce your liability, also a fence wouldn't be a bad idea ($1600+/-) - towers present an obstacle for youngsters to overcome. Lighting protection
Your tower needs to be properly grounded, entire websites and threads are dedicated to this topic, and I won't even dare to venture there. Equipment shelter
Will more than likely be required by development department with a minimum square footage. You can build this yourself or get a pre-fabricated therefore price can vary. ($400-3000+/-) Utilities
You will need to get power to your equipment shelter somehow, and this can't be done wirelessly. Insurance
It would be a good idea to get liability insurance on the tower in the event a youngster scales your fence and circumvents the no-climb guards.Conclusion:
Having your own tower is great but it will cost you considerably. These prices and conditions are from my experience in Central California - they may be different in your area. Your district may require more of you or considerably less. Investigate the matter thoroughly before you get started. I'm sure I've left some things out and would love to hear back from other readers with comments or suggestions. Either IM on DSLR, respond here or send an e-mail to scott at velociter dot net.
3 Radio power & other legal stuff
Can I legally modify my wireless network equipment?
This is tricky question to answer simply because the FCC hasn't been very specific about what constitutes a legal or illegal modification of FCC-certified wireless networking gear.
Manufacturers generally have to submit their products to the FCC to earn the "FCC-certified" bill of health prior to selling the equipment. Many consumers can now purchase wireless networking gear from stores such as Circuit City, BestBuy, CompUSA, etc. These units already have antennas built into them that obviously legally work with other accessories within the equipment line (i.e. same manufacturer APs work with their related PCMCIA cards, USB adapters, etc.)
With the recent articles being posted about how to conduct "war driving" (i.e. build a wireless radio which "sniffs" out wireless networks, etc.), extend wireless network ranges by adding more powerful antennas, etc., it's becoming apparent that the FCC will need to act soon.
Maximum power for 802.11
FCC limits for new 802.11a standard are different for 3 bands, as follows:
5.150-5.250GHz Indoor 50mW (17dBm)
5.250-5.350GHz Indoor/Outdoor 250 mW (24dBm)
5.725-5.825GHz Outdoor 1 W (30dBm)
An article in WNN WiFi Net News
In the 2.4 GHz band and parts of 5 GHz, the maximum power from the radio is 1 watt (W), and the effective power (EIRP) is 4 W on an omnidirectional antenna. (You can push far more power if you narrow the antennas beam. And parts of the 5 GHz band restrict radio power below 1 W.
What are the useful RF units of gain and power for the Wireless ISP?
Watts and dBm are units of power.
To calculate total output power, the dimensionless units dB and dBi are used.
How does one convert Watts to dBm?
Use a calculator, conversion table (pdf) or equation to convert the power units. Here is a short conversion table:
|0 ||.001 |
|15 ||.032 |
|24 ||.250 |
|27 ||.500 |
|30 ||1.000 |
|36 ||4.000 |
The equation is:
dBm = 10 * (log (1000 * P))
P = Power in Watts
1000mW = 1 Watt
Note, doubling the wattage increases dBm by 3. Here is a more comprehensive tutorial on Using and Understanding Decibels.
What is the maximum output power allowed for wireless Ethernet.
The maximum output power allowed for wireless Ethernet in the U.S. (802.11, 802.11b, etc.) by the FCC at 2.4Ghz is 36dBm or 4Watts.
From FCC Basics of Unlicensed Transmitters October 2007 (PDF File)
WLAN WISP interpretations
• Fixed Remote station can operate as a point to point system even if the base station operates as a point to multipoint system.
• Equivalent Antenna changes allowed without additional filings. See Section 15.204 antenna change polices.
• Adding additional amplifiers only allowed for 15.247 and 15.407 devices. Amplifier must be Certified with the transmitter per Section 15.204(d)1.
• All Sectorized systems are point to multipoint subject to 4 Watt EIRP limit except those systems that qualify as a Smart Antenna System (SAS). See SAS guidelines.
• For SAS system only, Prohibited Broadcasting does not include occasional broadcast management signals or
non-permanent multi-casting. See SAS guidelines.
How is antenna gain (dBi) measured and used?
The unit of antenna gain is dBi. dbI means "Isotropic", a perfect POINT SOURCE, which radiates in a spherical manner. A perfect dipole radiates with a donut pattern, broadside to the long dimension of the dipole. It is a relative measurement to an ideal dipole that radiates in a perfect sphere. To achieve higher gains, antennas are constructed such that they radiate more in one direction than another. An omni directional antenna radiates uniformly in the horizontal plane and radiates very little up or down. Panel, sector, yagi, and parabolic grid antennas radiate in cones of various widths. The higher the gain, the smaller the horizontal and vertical angles. Jerm gave the sprinkler head analogy: for a given amount of water, the distance the water shoots can be increased by focusing the spray; for a given amount of of microwave energy, distance can be increased by focusing the beam.
Antennas angles are specified by their half power point (3 dbi less than the specified max output).
For example, one '14 dBi' directional antenna has 14dBi gain straight ahead but only 11 dBi gain 32 degrees horizontally and 31 degrees vertically; one '24 dBi' parabolic grid also has 24 dBi gain straight ahead but only 21 dBi gain 6.5 degrees horizontally and 10 degrees vertically.Feedback Question:
please provide with the formula to calculate the gain of the antenna in dBi .....
No simple answer - see the following forum thread for more information: »Forum FAQ - pending feedback...
What other power losses are there?
Connector losses can be estimated at 0.5 dB per connection. Cable losses are a function of cable type and length. LMR400 is nominally 6.6dB loss per 100 feet.
How does output power relate to distance?
The rule of thumb is that increasing output power by 6dB doubles distance. (However, I can't find a document-able source for this rule.)
How can the above be used to calculate output power?
Example 1: PC Card alone
Output power for a Lucent/Orinoco/Agere/Avaya 802.11b PC card is 15 dBm. If there is no external antenna then that's the answer. 15dbm.
Example 2: PC Card with 14 dBi external antenna and 50 ft of LMR400
Assumed total lost for a pigtail adapter is 0.5 dB. Loss for each connector on LMR400 is 0.5 dB.
+ PC card - pigtail adapter - connector - 50 ft LMR400 - connector + 14 dBi antenna = ? Total output power
Substitute the six items above with their 'db-counterparts' with + for things that add power and - for losses
15 dBm - 0.5 dB - 0.5dB - 3.3 dB -0.5 dB + 14 dBi = 24.7 dBm
Example 3: PC Card with 24 dBi external antenna and 50 ft of LMR400
15 dBm - 0.5 dB - 0.5dB - 3.3 dB -0.5 dB + 24 dBi = 34.7 dBm
How is output power calculated when an external amplifier is added?
Most amplifiers used for Wireless ISP purposes (including 2.4Ghz flavors) are rated for output power. Therefore, input power and losses prior to the amplifier can be ignored. Typically, the amplifier is mounted very close to the external amplifier, without any extension cables or extra connectors.
Example 1: PC Card with 0.5 Watt amplifier and 8 dBi external antenna.
Note, 0.5 Watt = 27 dBm.
+ amplfier output + 8 dBi antenna = ? Total output power
27 dBm + 8 dBi = 35 dBm
Example 2: PC Card with 1 Watt amplifier and 6 dBi external antenna.
30 dBm + 6 dBi = 36 dBm
Can splitters be used? What happens to output power with a splitter?
For a given input power, a two-way splitter will typically decreases output by 3.5 db, three-way by 5.3 db and four-way by 7.5 db.
Example 1: PC Card with 1 Watt amplifier, three way splitter and three 11 dBi external antennas.
Each tap off the splitter goes to one sector antenna, the output power is the same for each antenna:
+ amplifier - splitter + antenna = ? Total output power
30 dBm - 5.3 dB + 11 dBi = 35.7 dBm
What are the FCC equipment certification requirements?
Clarification on FCC Requirements
We have been investigating the exact requirements (as of now) for the Part 15 radios used in WISP deployments. To try to clear things up some, I decided to try to summarize what we have learned over the past year or so and try to help others to understand exactly what is required and expected. That said, I am not a lawyer and my general disclaimer would be to use this information as a guide and not as the final word. The final word, as always, resides with the FCC in the USA and other regulatory organizations in other countries.
To spell it out:
DISCLAIMER: THIS INFORMATION IS INTENDED AS A GUIDE AND FOR DISCUSSION PURPOSES ONLY. THIS IS ONLY MY OPINION AND ANY INTERPRETATION IS ULTIMATELY UP TO THE FCC ONLY!
All that said, FCC certification can really be broken down into two parts: Subpart B and Subpart C certifications.
Let's take a look at what each of those is:
- Subpart B:
This is for unintentional radiators, meaning that any electronic devices that have signals will put out interference. Because of this, the FCC requires this interference to be measured to make sure it complies with the guidelines that have been set by the FCC.
- Subpart C:
This is for intentional radiators, meaning that the device is intentionally transmitting RF (AKA a transmitter). The FCC has set certain rules for these transmitters based on band, modulation, etc.
Now that we know what the two parts of certification, we can talk about what the requirements for each are. There are two types of devices on the market today (that I'm aware of at least): complete systems and certified modules.
- Complete systems are those systems that are certified as a whole; meaning that the certification includes everything from the power supply, to the enclosure, the radio card / PCBA, pigtail, etc. It was tested as a complete system and is therefore marketed as a complete system. Any changes to the complete system (enclosure, antennas, etc.) void the certification and must be re-certified. There are exceptions to this which are covered later. Complete systems carry an FCC ID that covers Subpart C requirements and a Declaration of Conformity that covers Subpart B requirements.
- Certified modules, on the other hand, have been tested to meet the standards as a stand-alone device. For example, a mini PCI card may have been tested without any housing, etc. There are certain requirements that must be met in order to be certified as a module, but once it is certified, all Subpart C requirements are met automatically when the module is integrated into a final system as long as the stipulations written on the grant are met. In this case, the module carries the FCC ID label to cover Subpart C requirements. In order to meet Subpart B requirements, however, the final system MUST STILL BE TESTED and covered under a Declaration of Conformity. The final system must also have a label on the outside that says: Contains FCC ID: xxxxxxxxx. The grant notes section of the FCC grant must say Modular Approval.
There are some exceptions to these rules. For antennas, any antenna of the same type and lesser gain may be used with either a certified system or a certified module. By same type and lesser gain, it means that if the certification has a 12dbi Omni, other omnis that are <=12dbi may be used by the installer. Also, different lengths of coax can be used with certified systems and modules.
So what does this really mean for the WISP? It ultimately means that the device you are using must either:
- Have a modular certification for the radio inside AND have a Declaration of Conformity to comply with Subparts C and B respectively OR
- Have a system certification for the complete system (covers Subparts C and B both)
The easiest way for a WISP to tell if a system is FCC certified is by the required label on the device. For #1 above, there should be a label on the outside of the device that says Contains FCC ID: XXXXX and have the Declaration of Conformity on the label as well or in the manual. For #2 above, there should be a label on the outside of the devices that says FCC ID: XXXXX and have the Declaration of Conformity on the label as well or in the manual.
My final comments are on changes and what it means for the certification. I have created a matrix that covers complete systems and certified modules as well as some common changes:
As I said before, this is to be used as a guideline. If you have specific questions or concerns, you can ask the FCC lab directly at this link:
This site contains the FAQs for most of the items covered above as well as a link to Submit An Inquiry on the left nav. I encourage all of you to read through this information and ask questions if you have them.
To search for FCC grants, you can use this site:
I hope this information helps to give you a better idea of the FCC certification requirements!
What are the power limits in Australia?
4 Bandwidth management
How can I do bandwidth management with Linux?
Can Squid be used to manage bandwidth?
Squid can be configured to use delay pools to provide a way to limit the bandwidth of certain requests based on any list of criteria. Delay pools are described in section 19.8
of the Squid FAQ
For those not familiar with Squid, "Squid
is a full-featured Web proxy cache, designed to run on Unix systems, free and open-source software."
Superdog1 gets the credit for pointing out Squid as a bandwidth control technique.
What are the different types of BackBone connections that typical WISP's use
Here are some of the typical BackBone connections that WISP's use: SDSL (Symmetrical Digital Subscriber Line):Speed:
128Kbps up to 1.1 MbpsPros:
- It can go about the same speed as a T-1 at a fraction of the cost.
- In many cases it can be installed very fast
- Easy Installation
- Ping times are not as good as many T-1's
- Many providers do not allow resale of these lines, so you have to be careful
and check the TOS
- Downtime maybe greater then that of a dedicated line
- Speed is usually NOT guaranteed
- Not available in a lot of areas
For startup WISPs who would like to provide service to a
minimal amount of people or who don't have the justification for a T-1 yet at
the time of service.
56 kbps to 1.5 MbpsPros:
- Low Latency (Good Ping times)
- Speed is guaranteed
- Dedicated line (Great Tech Support, compensation for downtime)
- Available in almost all areas around the US
- High Cost
- Tech Savvy setup
For WISPs with a good customer base that are ready for the next step.
Bonded T-1's (Dedicated):Speed:
3 Mbps to 6 MbpsPros:
- Low Latency (Good Ping times)
- Speed is guaranteed
- Dedicated line (Great Tech Support, compensation for downtime)
- Available in almost all areas around the US
- High Cost
- Tech Savvy setup
This is for WISPs that have exceeded or are projecting exceeding the maximum capacity of a T-1 in the near future, but can not justify
the cost of a T-3 yet DS3 Usually, they just add T-1's and bond them to make it fast, so the lowest speed would be around 3 Mbps, so that would make the cost double in most situations.
12 Mbps to 45 MbpsPros:
- Low Latency (Good Ping times
- Speed is guaranteed
- Dedicated line (Great Tech Support, compensation for downtime)
- Available in almost all areas around the US
- High Cost
- Tech Savvy setup
This connection is for WISPs who have many customers and
are ready for a much faster connection. A T-3 is a big jump from a SDSL
connection or say a T-1 or a Bonded T-1, so don't buy a T-3 until you are sure
that you have enough users to pay for the connection.
53 Mbps to InfinityPros:
- Low Latency (Good Ping times)
- Speed is guaranteed
- Dedicated line (Great Tech Support, compensation for downtime)
- Available in almost all areas around the US
- VERY High Cost
- Tech Savvy setup
A very fast connection with a very high cost. DO
purchase one of these connections unless you have SUBSTANTIAL
financial backing!!! These connections require very expensive routers, and
a lot of technical experience just to get them to work.
T-1's and T-3's are sometimes referred as DS-1's and DS-3's respectively.
Hopefully this FAQ will give you some information about the different types
of connections that are available.
5 What to do and what not to do
How to be Perceived as a Good, Reliable WISP
Here are some thoughts on how we have "migrated" to a more reliable network.
The difference is in the following in no particular order of importance: redundancy, provider, wireless equipment, policy, tech support, network management and reporting.
I'm going to leave out standard business stuff and focus on the above categories.
Back in the day we had one of everything and if it failed we had to drive/climb to the point of failure and fix it or lose customers.
Now we have almost two of everything. It's not as expensive as it sounds and takes a huge load off of us in terms of response times. It also appears to the customer that no downtime ever happens.
We do this by having two boarder routers configured in tandem (ours is VRRP, your may be hot fail, or BGPed). We use Mikrotik on pentium servers so the costs is hundreds, not thousands of dollars.
Our backhauls are configured in a wireless ring in case one fails (we use RSTP in bridged networks, OSPF in routed). The third or more leg in the ring can just be a low cost low bandwidth link if necessary as long as it can keep the customers going while a repair is done.
Our sectors are doubled/overlapped so that CPE's can see more than just one AP. Capacity is kept under maximum so if one fails the other AP can temporarily handle the load. Having overlap and keeping sector count low does use a bit more frequency, but generally allow for greater speeds per customer.
Network layout in general has a dual/split path for every client from CPE to the internet is the idea. So if you have two AP's facing a section for redundancy plug each one into a different router/switch in case of router/switch/cable failure.
IP space directly from ARIN split among two or more providers assures that your public IPs will not be unreachable in an outage of one provider. This is usually done with a BGP protocol at the ISP. Or simple hot failover to another provider creates better uptime.
This one is critical as it's what you are selling in the end. In the beginning we had a DSL line with a few public IPs. Now we have access to a 2.5Gbps fiber line and upgrades to a BGP address space.
Your provider has to be able to handle the capacity it is selling you AND have the same features you are selling your customers. If they can't uphold their end of the bargain then you won't be able to either for your customers.
Upgrade your provider sooner rather than later and get the best you can afford.
We started with 802.11b and have had to migrate to Canopy for various reasons. Take careful stock of your service area and use the right equipment for the topology and environment from the beginning. Whether that is 802.11, mesh or proprietary stuff.
This is a hard one to figure out, but lots of reading, planning and some testing before deployment will give you a head start. Even then a curveball will probably come your way in the form of a manufacturer suddenly leaving their platform in the dust or spitting out crappy PCB's etc.
If possible use a blend of two topologies and manufacturers. Then if something really goes wrong you still have something to work with instead of starting completely over.
Make sure your chosen distributor and manufacturer has a good track history, company record and RMA policy.
No matter what we do, you can't please everyone all the time. But setting the proper expectations up front will help down the road. Your customer's perceptions are set by the industry, marketing (yours and competitors) and whether they woke up on the right side of the bed etc.
Get a written policy SLA/Terms of Service together to define WHAT it is you are selling and NOT selling. And then treat that like your company bible with few exceptions.
Eventually the disgruntled customers will come to respect it and your company.
Some examples are pricing, speeds, installation procedures, equipment ownership, TECH SUPPORT, disconnect policies etc. etc.
Make sure your policy is reflected in your web site, written documentation, sales call, tech support visits, the whole enchilada. Consistency is key.
This deserves a whole separate thread, but the important point is to commit to it. Even if your policy says the customer can take a flying leap off a tall cliff, go the extra mile and earn their appreciation.
A few minutes more on the phone or an on site visit will usually be greatly appreciated. Even if the customer wants you to come re-configure their router after hours for no extra charge (why DOES everyone expect this for $24.95 a month?), bite your tongue until it bleeds and politely schedule a time and price according to your policy (you have that in your policy, RIGHT?).
The bottom line with tech support is to give a little more than expected or per policy to create the proper perception. Tell them your hourly rate for non customers is $150 an hour, but for them it's $55 or $90 if they want emergency service (as per your rate policy).
If someone returns the phone calls or answers the phone within reasonable times (again, whatever expectation has been set) then they will feel good about it.
Good tech support leads to referrals in our experience.
NETWORK MANAGEMENT MONITORING AND REPORTING:
In the beginning we didn't even have an idea of how much bandwidth was being used and no real time or historical charting. What can you tell your customer without having this information? "Uh, you're down again? Since when?" is not a good response.
Even most of the inexpensive CPE/AP/Router/Switches today have SNMP or can be pinged using some monitoring program like MRTG.
The customer will actually listen and respect your expertise if you can tell them more information than they already know. "Your radio has been up for 21 days, 2 hours and 32 seconds and is running at 100 percent" stuns them to silence (sometimes).
Monitoring is the dividing line between what's your responsibility and theirs. What's free support to fix your end or paid support to fix theirs.
Get equipment and software that allows you to control your network. Nothing like watching your network get crushed by that one user running 1000 simultaneous connections on their Azereus BitTorrent client. Or that collection of customer Netgear routers that suddenly decide to ICMP blast the entire broadcast domain for days on end.
Usually this means proper traffic shaping and routers/managed switches at key points in your network. I can't speak enough of how Mikrotik shaping has improved our network capacity and reliability (or any similar product).
Traffic shaping, managed switches and proper use of routing/vlan techniques keep the nastyness of virus/icmp/arp storms at bay. P2P is allowed on our network and keeps the power users happy along with the business and casual residential users.
Live packet reporting like Wireshark and Mikrotik Torch allow complete investigation of what is happening NOW in the network. Historical graphing of SNMP and programs like NTOP/MRTG data gives us the complete picture over time.
To sum it up we wouldn't be where we are today without adhering to these principals. I hope the information can help someone else improve their operations!
How to ground an antenna and spark arrestor
You will never believe this one!!!!!!!!!!!!!
I did an install yesterday and when I was done running the LMR400 in the house(I pull a small gauge wire into the house with it to ground the spark arrestor)and the USB adapter was up and running I went outside and grabbed the large #6 copper coming off the roof and attached it to the grounding rod that I had just pounded in and everything was great.I then reached over and grabbed the smaller wire(#14)and stuck it down to the rod and MY HAIR STOOD STRAIGHT UP and I got ZAPPED!!!!.I wont post my exact words here but it went something like this"WHAT THE!!*%",after I regained my composure I went and got my multimeter and to my suprise there was 110 volts coming thru this wire!!!!(it was already attached to the spark arrestor).We turned the computer off and I STILL had 110v!!!.It only went away after we un-plugged every device hooked to the computer(this guy had like 20 things attached),as it turns out the ground in the house was not right and every item in that room was plugged into a circuit that only had a neutral(white) and a hot(black)coming to the outlet with no ground!!!!.The moral of the story is to be damn careful when doing installs so that You dont get a free perm!!!.If You do not see a grounding rod already being used outside where the service comes in-DO not ground the spark arrestor outside!!!,Use the COLD water pipe and the problem should be solved!,Tim
Wireless ISP and interference from cordless phones
Be aware that some wireless ISP's use the same frequency range as the newer 2.4GHz cordless phones. If you are having problems getting a decent signal and/or upload/download rate, and especially intermittent problems on the customer end, make sure nobody is using 2.4GHz cordless phones.
How do I upgrade the Linksys WET11 to the latest firmware?
First thing I do is upgrade the firmware on the WET11 board to 1.43 here: »www.linksys.com/
Next I open up the WET11 and take out the bromax pcmcia card that is inside, and install it in my laptop. I got the windows drivers from here: »www.bromax.com/
Next I go to demarctech and get updated station/primary firmware.
That zip file from demarctech should come with station firmware 1.1.0 and primary firmware 1.4.9. It should also come with a program with winupdate that you use to load those firmwares to the bromax card.
After you do all that just throw it back in the WET11 and it should work. Please keep in mind that changing the WET11 in any way may not be FCC approved
How do I install a mast on a roof with guy wires???
When installing guys on a roof or any wood covered surface, you MUST catch a rafter!!! If you don't, you will be fixing it and using your insurance to fix a ceiling! Guy Wire Class 101
•When installing any eye hook in ANY roof, it MUST be in a rafter! If you can not hook a rafter then you have to cut a 2x4 and nail (screw is better) it in place between the 2 rafters so you have a solid place to screw the eye hook into! (if you are in a high wind zone, make sure the rafter you are hooked to has a "hurricane strap" attaching it to the top plate on the structure).•Make a small pilot hole into the roof and then turn the eye hook into the hole. Then un-screw it and squirt a large amount of silicone into it (Not the cheap stuff! Geosill 2000 works great for this - it doesn't get hard). Turn the eye hook into the roof - as you do this, you will pull the sealant down into the threads•Crawl underneath and make darn sure that the hook has caught the rafter or the piece of wood that you have screwed in place between the 2 rafters!•If you are using a hinge, make sure that at least half of the screws that you have used are in a rafter! (I say this because sometimes the center of the roof has no rafters, hence the piece of wood between the rafters). UPDATE: DO NOT use a hinge! It has come to my attention that hinges are NOT covered by ANY of the mast manufacturer's warranties! If you try and expand the mast all the way and then "swing" it up it won't work and will bend in half!!!!!•If you are using a mast that is 30' or over, I would drill a hole for every eye hook and use an eye bolt. This allows you to push the eye bolt thru and attach it with a washer and a nut on the bottom. This is a much more stable system.•Do NOT screw an eye hook into the roof decking alone and expect it to hold! On a lot of the newer buildings, they use Aspenite (flake board or OSB) and this stuff is JUNK! It can barely hold up the roof, much less an eye hook trying to hold up a 20' mast with 60 mph winds blowing against it! Even if the roof is decked with 5/8" marine grade tongue and groove plywood it will not work!•All of your guys must be centered with the mast. On most 20' masts, you will have 2 sets of rings that will allow you to use 4 wires at every ten foot level. Do NOT think that you can put up a 20' mast and only guy it at the top! (you WILL be putting this back up with the first strong wind!)•When setting up the mast, make sure that it is plumb (straight up and down) before tightening the guys.•After you have set everything up and it looks really good, go back and check it again! (With a 40' mast, you will have at LEAST 64 U-clamps holding the wires in place - 2 at the top and 2 at the bottom of every wire minimum! Make sure that all the clamps are tight!)•Only use the stranded wire (Airplane wire) to erect your mast. The cheaper stuff stretches and will become slack after 30 minutes.•Always use the heaviest turnbuckles that you can find to adjust the tension (without overkill of course!)•After you are done adjusting the tension you MUST lock the turnbuckles in place so that the wind can not wiggle them and loosen the tension. This can be done buy using a small piece of wire and looping it thru the top and bottom eye hole of the turnbuckle and twisting it together so that no movement is allowed.
I guess the moral of the story is this: Do it right the first time
or you WILL be back up there at 2AM on the coldest night of the year fixing it!
Grounding dos and don'ts
Collection of Grounding Threads
6 CPE installations
what not to do on a WISP install
OK, Things NOT to do on an install:
All right, Here we go, after today's events here is a list of the top 10 things not to do when at the customer's location (#1 happened today!!!)
10. Forget to close the door and let the family pet get away!(then chase it for the rest of the day)
9. Unplug a large freezer full of frozen fish to plug in your extension cord for your drill. Forget to plug it back in and leave. Phone call WILL follow about 3 weeks later-YEEECH!!!!
8. Leave full tube of silicone on the deck with it loaded into gun and open. Lose your mind when you are on the roof and the resident 3 yr old squeezes the entire contents of the tube onto the sidewalk. For an added bonus, don't see it until you step in it!!
7. Step in a LARGE pile of dog $#!t and then walk through their living room and down the hall! (carpet is white OF COURSE!)
6. Leave a large roll of mastic laying on the ground. Listen to screams of terror as Sissy strips the hair off of her 2 yr. old brother's arm with it (heard from the roof of course)
5. Measure your cable 4 times just to be sure and cut it off,hook up antenna and feed the cable down only to find it is still a foot short.
4. Put Your handy dandy Burnz-o-matic pocket soldering iron down on the table thinking it was not lit anymore-come back in 5 minutes and find it and a large pile of white plastic on the deck.
3. Lay a large screwdriver on the roof thinking it wont go anywhere. Screwdriver rolls off the roof and you say, "I'll get it later". Climb down off the roof and find the screwdriver sticking in the dash of the convertible in the driveway.
2. Put down the extended 15 ft mast on the roof for 2 seconds to adjust the brackets on the chimney, watch it slide off and impale the above ground pool. Enough said - you figure out what happens next!!
1. And the #1 thing is something that I did today (Yes, I am an idiot but at least you may laugh at it and it will brighten your day!) Make damn sure that the steam line for the hot water heat is NOT directly behind the wall that you are drilling a half inch hole through - it makes a Hell of a mess.
7 Miscellaneous Questions
What's the difference between "dB", "dBm", and "dBi"
I keep seeing people using the terms "dB", "dBm", and "dBi" interchangeably, when they actually mean very different things. So, here's a little background on the correct usage of the terms. Sorry if this is covered in the FAQs and links, but from the posts here, I don't think people have read them thoroughly.
A dB is a RELATIVE measure of two different POWER levels. There's also dB relative to VOLTAGE levels, but I won't go into those, as we're mostly concerned with POWER levels in our discussions here. 3dB is twice (or half) as much, 6dB is four times, 10dB is ten times, and so on. The formula for calculating gain or loss in dB is: 10log P1/P2. It's used for stating the gain or loss of one device (P1) IN RELATION to another (P2). Thus, I can say that an amplifier has 30 dB of gain, or I have 6dB total feedline loss. I CANNOT say, My amp puts out 30 dB, or I have a 24dB antenna, as you must state what you're referencing it to, which is where the subscript comes in. The dB by itself is not an absolute number, but a ratio.
For amplifiers, a common reference unit is the dBm, with 0dBm being equal to 1 milliwatt. Thus, an amp with an output of 30dBm puts out 1 Watt. How much gain it has is a different matter entirely, and you can have two different amps, each with an output of 30dBm (1Watt), that have different gains, and require different levels of drive power to achieve their outputs. You can also have two different amps with the same gain that have different output powers.
There's also dBW (Referenced to 1 WATT), but you generally only use those when dealing with Big Stuff, as 30dBW is 1000w, and way beyond what we deal with here!
For antennas, a common reference unit is the dBi, which states the gain of an antenna as referenced to an ISOTROPIC source. An Isotropic source is the perfect omnidirectional radiator, a true Point Source, and does not exist in nature. It's useful for comparing antennas, as since its theoretical, its always the same. It's also 2.41 dB BIGGER than the next common unit of antenna gain, the dBd, and makes your antennas sound better in advertising. The dBd is the amount of gain an antenna has referenced to a DIPOLE antenna. A simple dipole antenna has a gain of 2.41dBi, and a gain of 0dBd, since we're comparing it to itself. If I say I have a 24dB antenna, it means nothing, as I haven't told you what I referenced it to. It could be a 26.41dBi antenna (24dBd), or a 21.59dBi (also 24dBd!) antenna, depending on what my original reference was. The difference is 4.81dB, a significant amount. Most antenna manufacturers have gotten away from playing this game, but the reference will be different in different fields.
Commercial antennas tend to be rated in dBi, as the people buying them understand it, and Amateur Radio antennas tend to be dBd, as Hams are very familiar with dipoles. Sorry to go on for so long, but as an Engineer, it bugs me a bit to see things like this!
Thank you to drjim
for this information.
Bridging or Routing Your Network
To Bridge or to Route?
Routing means deciding at each interface in a network where the packet is intended to go. Usually when we talk about routing we mean IP routing. That is the "kind" of routing I will be talking about. IP routing happens at layer three in the OSI model, it has nothing at all to do with the MAC layer. Routing divides broadcast domains. This means that ARP traffic stops at the router. ARP traffic is a layer two function used to discover which MAC host has a specific IP address. In large bridged domains (broadcast domains) ARP traffic can generate substantial network traffic.
Bridging means repeating at each interface in a network all packets which appear on one side to the other side. A bridge is a repeater. A hub is a "multipoint" repeater. You plug in eight wires on a hub and a packet coming into any wire goes out the other seven. Bridging happens at layer two in the OSI model. That is the MAC layer. It has nothing to do with TCP/IP. As an aside, all this means that a layer two switch is in actual fact a layer two router because, a packet coming in one port on the switch is only repeated on the port where the destination computer is connected. The layer two switch "routes" packets between ports using MAC addresses and the spanning tree protocol. Layer two switching is easily a whole order of magnitude faster than IP routing because IP routing requires a lot more CPU and a lot more software.
Now that we understand what bridging and routing are for our purposes, lets have a look at how they play together to move packtes to the right hosts.
When a computer wants to communicate with another computer using TCP/IP. It goes thru the following process:
1) Check the destination IP address and compare it with it's own IP address and netmask to see if it needs to send it to it's gateway. If it knows it's gateway it will go to step number 2, if it doesn't know it's gateway it may send an ARP request out and the gateway can proxyarp for the remote host, which is essentially skipping to step number 3. What happens in this unusual case is that the gateway "spoofs" the local host into believing the remote host is on the local segment. Always set your default gateway.
2) If the remote host is on a different IP network, contact the gateway computer and forward it to the gateway computer for ROUTING to the remote host. This is done by sending a packet with the gateway's MAC address and the remote systems IP address to the gateway via the MAC address of the gateway. The gateway (router) understands what to do with such a packet.
3) If the remote host is on the local IP network, check the ARP cache and see if it has an MAC/IP pairing in the cache for that host.
4) If it has the MAC/IP pairing for that host prepare the packet and send it DIRECTLY to that host. Note that it uses the MAC address to accomplish this.
5) If it does not have the MAC/IP pairing in the ARP cache, send an ARP request. When the other computer hears the ARP request it responds with an ARP reply, the local machine sticks the MAC/IP pairing in its ARP cache and then it talks directly to the remote host. Note again that all computers on the local network communicate using MAC addresses.
A couple of things stand out here. How can a computer know that an ARP request is for it? Well, every computer on the LAN listens to FF:FF:FF:FF:FF:FF (the MAC broadcast address) and the ARP request goes to that address. The ARP request looks sorta like this, "Yo' alla yall! Who has IP ADDRESS 18.104.22.168?" The ARP reply looks sorta like this, "Ayup! IP ADDRESS 22.214.171.124 is at MAC ADDRESS 01:20:03:40:05:60."
Now since that ARP request goes to the MAC broadcast address, it is repeated across every bridged or switched port in the entire LAN. This is one place where problems can show up.
For example, suppose you have a Cisco router you use to bridge 120 DSL clients onto your network. All of those customers are on the same T-1 circuit on that router. That T-1 is carrying frame-relay back to each subscriber. Essentially you have 120 subscribers sharing 120 different LOGICAL circuits on that T-1. There is no way for the router to know which MAC address is on which IP address at the far end because it is bridging. Therefore when ONE ARP request goes to that Cisco it has to repeat that single request 120 times, once for each logical connection across that T-1. That is 120 packets. Now imagine that a worm scans your Class-C and causes your gateway router to generate fifty ARP requests in one second. That causes the bridging Cisco to generate 6000 ARP packets across that T-1. Clearly bridging can be a problem in a busy network.
Now suppose that we had the exact same Cisco router but rather than use it to bridge those DSL subs onto the network we use it to route those subs onto the network. We subnet our Class-C network and use the top 128 addresses behind the Cisco and the bottom 128 addresses in front of the Cisco. This means we need to run some kind of routing protocol on the main network or we need to set static routes in our primary router(s). Our centralized DHCP server will no longer work because DHCP is a LAYER TWO protocol and is not broadcast across routers. We solve this by running a DHCP server(s) on our client facing Cisco(s). We do need to ensure that their pools of addresses DO NOT conflict with one another. DHCP makes provisions for this. We now must require customers to login using RADIUS or some other routable authentication protocol, or via a captive portal. To reduce our problems with ARP storms we have substantially increased our maintenance overhead.
Wouldn't it be sweet if we could have our cake and eat it too? I want to bridge these DSL subs onto my backbone and force them to login before they can go anywhere or do anything. I want to be able to hand them an IP address by looking at their MAC address or by reading their user name during login. I want to eliminate ARP storms caused in situations where multiple logical connections cross one physical link. I want a centralized server in my main offices which lets me completely control every aspect of each individuals traffic because every packet passes thru it. I want to be able to firewall them, shape their traffic, turn off their account, and account for their data. I want to know who is logged on which logical port and to be able to sniff that specific port with little or no hassel so that I can identify the one with a worm quickly and disable the account as quickly.
Enter the PPPoE server.
PPPoE (Point to Point Protocol over Ethernet) is now built into Windows XP and RP-PPPoE is a free aftermarket you can add to W98, WMe, W2K. You can build your own PPPoE server using Linux or FreeBSD. A PPPoE server allows you to logically bridge your clients to a host in your NOC where it logs them in, gives them an address, and does whatever else you can do with a Linux/FreeBSD box.
You don't get ARP storms because everyone is using the MAC address of the PPPoE server on the public side of the PPPoE server (essentially layer two NAT) and the PPPoE server knows which MAC addresses have what IP addresses all the time. You can assign NATed non-routable addresses to some users and public routed addresses to other users and you can firewall as desired by individual user login.
Why is this cool? It is a hybird. It lets you bridge your clients to a single server where you make all the decisions. Your clients can't talk to each other unless the PPPoE server allows it, even if they are actually associated with the same access point, because all IP traffic must go thru the PPPoE server. It lets you allow anyone to associate with one of your AP's but if they don't have a username and password they can't get an IP address and if they forge an IP address they can't get past the PPPoE server. This means any subscriber of yours can connect to the Internet from anywhere in your network.
That's the holy grail, transparent roaming at layer two.
I built a PPPoE server and we have been running it on our network for a few months now. Since we are a RADIUS shop, I configured it to use our RADIUS server as it's source of authentication data. I am quite pleased with the control it gives me. We are busily moving all of our DSL subscribers over to it and we are now experimenting with micropops backhauled via DSL thru the PPPoE server. Folks, this is the ticket. Do you want to stick a dumb AP in the parking lot of an apartment building and let multiple clients login to your network in such a way that if one of them gets a worm you will know which one it is? You can do that with a PPPoE server. Do you want to place a half dozen AP's in a neighborhood and let anyone who has an account with you access your network from any of those AP, while roaming freely? This technology will do that for you.
But the question was do I bridge or route? I think you bridge where you should bridge and you route where you should route, choose carefully because the answer is not obvious most of the time.Credit to DaDogs (Michael) for this one!
Getting started using Radio Mobile
Okay, so you want to start using Radio Mobile.Radio Mobile website
Here I'll show you some screens of where to find the options to make a basic link.
I'm going to start off assuming you know how to extract, install the program, and obtain your GPS locations via Google Earth
, but will guide you as to getting terrain data. You're not going to learn this in one day, it took me about two months to get fully comfortable with the program and remember the screen layout. I also found very little as far as FAQ's and guides so I am basically self taught and I don't know every little detail of the program.
When you first open the program you're going to see a map of the grand canyon. This is just an example and the first thing you're going to have to do to make your own is make sure your terrain server is setup. RM will automatically download the appropriate terrain file.
First go to Options, Internet
, under SRTM
• USGS USA 1 achsecond or
and enter this URL:
f t p://e0srp01u.ecs.nasa.gov/srtm/version2/SRTM3/North_America/ (If you copy/paste the URL be sure to remove the spaces in "ftp")
I have found that using #1, the maps can be about 7 MBs
while #2 can have maps around 800K.
Now make sure 'Download from the internet if a file is not found on local path and keep a local copy'
Now after that click on the blue right hand arrow (
button - see #1 in the toolbar image below).
This will open a new window shown below.
This is where you tell RM what map you want to download by GPS coordinates and set the size and distance of the map. Now all the options you see in the picture are what I would recommend, for longer links, such as 15 miles, you would need to set the Height in Km to about 30 Km. But for 2-4 miles 15 Km is fine. Make sure 'Merge Pictures'
is checked, and enter your GPS coordinates. Then click 'Extract'
Now a map should present itself with a new window, if the image is all blue then the program did not find the terrain data, this can be from either a bad server, you set up the Other
with a bad link, or the server does not have the data. You can go back under Internet
and change to a different server but the two others I previously mentioned are the best I've found.
But if all is well let's continue..
it gives you many choices, this is how the map will be laid out, either the new street map you download will be 'merged' into the data map, or be completely replaced (You can go back and experiment more with this later). I like Add
because it retains the terrain color levels. I use the Mapquest
option, but you can also use MapPoint
. Only those two are worth trying. Click Draw
and it will download, and merge the two into one.
Then click 'Keep in actual picture'
Congrats, you now have your map and terrain! Looks nice huh?
Okay, let's place some radios. Click on the map and click the
button at the top (see #2 on the toolbar image above).
This is where you place your radios, either by GPS or your mouse position. Click 'Place unit at cursor position'
Then Okay, it will add a radio to the place you clicked, click a new spot and do it again with the next unit down selected.
Now let's setup a network. Click on the
button (see #3 on the toolbar image above), this is Network properties
Set the minimum and max frequencies and the amount of forest if you so desire. Note that even 100% forest does not mean it's going to actually represent dense forest throughout the map.
Then go to 'Systems'
I'm not going to go over this much because this is for someone that knows what antenna gain is and dBm power levels. Just make sure you have your antenna type selected under 'Antenna Type'
and set the Height.
Now go to 'Membership'
This is a very important part. It will tell the program which radios will link to each other and what azimuth the antenna will be at, fixed or not.
Now check both your units you placed on the map and change the 'System'
selection to the one you edited earlier for Both units. Make sure 'Fixed'
is unchecked for both units and select which unit they will be pointed at.
For example Unit 1 should point at Unit 2 and so on..
and you're done!
You should now see both your radios with a line between them. Now click on the
button (see #4 on the toolbar image above) called 'Radio Link'
. This will show if the terrain is blocking the radios or not, and if you added trees RM will add a certain amount of loss.
Now marvel at the fruit of your labor and enjoy.Remember,
When you're done, Save the .Net file. This contains all the GPS coordinates and other data besides terrain.Double click (older versions) or Shift click on a metric field to have a metric to standard converter appear.
Compiled 9/1/2006 using RM ver. 7.5.6
Forum threads with more information about Radio Mobile:
»Radio Mobile Deluxe Install and Setup
»Radio Mobile Deluxe (modeling software)
Are there any Mikrotik backup scripts I can use?