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2. DSL 201
If you are going to be operating servers I would suggest SDSL if you can get it, not only because the maximum upstream speed is generally faster than ADSL, but because your DSL provider is more likely to understand your needs, give you a fixed ip and be more responsive to technical problems.
VDSL is a DSL technology like ADSL, SHDSL etc. and is used on copper wires, although fiber is usually used to connect the VDSL DSLAM to the world. It runs to 56mbits and will support 4 TVs (loads of channels), phone integrated to the TV (caller ID on the TV screen) and 1meg up and down for PCs.
The difference between dynamic and static IP addressing is that, with a static address, your computer gets an IP number (the Internet equivalent of a telephone number) that is all its own for as long as you are a customer of that provider. Dynamic addresses can change (more often than not they don't, but this isn't guaranteed either), usually through a technology called DHCP.
Another wrinkle in all this is that some ISPs provide IP addresses that don't change, yet they are still dynamically assigned via DHCP. People often confuse these "fixed dynamic" IP addresses with static IP addresses.
Dynamic addressing has the drawback that if you're trying to run any kind of server (web, mail, gaming, etc) your computer will be more difficult to find as the people connecting will need your current address to connect. There are services such as DynDNS and DHS (free) that facilitate giving your dynamic address a name that everyone can consistently use.
There's no difference in speed or, usually, service between static and dynamic addressing, as its simply a method of giving your computer a destination address on the Internet.
SDSL has upload speeds almost the same as its download speeds. This makes it optimal for gaming and servers of any type. Because the upload speed is high it is more expensive than ADSL.
For most uses ADSL is the best choice.
thanks and regards, Sahir Hussain IT Engineer
simple but brilliant answer.. thank u..
short and powerfull
Thanks,..to the point and brief! thanks!
what is this
RADSL typically can reach further than higher speed ADSL lines due to its nature of throttling down when line quality is variable.
To some extent, also, IDSL prices maybe higher because they can be: IDSL is often the only choice if you are sufficiently far away from your CO.
If a mix of gaming and download and general usage is more important, you may be happier with ADSL because you can still get low pings, and you can get the faster downloads.
If they cannot answer this question clearly and immediately, do not choose them for your DSL service.
One of the main deciders though, is price ... for some reason, SDSL lines are considerably more expensive than ADSL lines, so unless you have a specific need for upload capacity, concentrate on the best value for money in ADSL services, then pay more for more speed if you can afford it.
If you insist on some rules of thumb: a small office can be reasonably happy with even a 144k IDSL line, if they are just "using the net" as a reference tool ... more than two people are unlikely to be dragging down web pages at the same instant.
On the other hand, a single user who is addicted to mp3s or large game demos, or who swaps video streams, would fill a connection ten times that IDSL capacity.
Try one of
•Globesoft Multi-Net Manager, www.globesoft.com/Common/frm_products.html
If you are still stuck, try this resource
Switching network settings on a laptop computer.
Line sharing installs will still require you to carefully follow installation instructions (connecting your PC, putting micro-filters on your other phone sockets and so on), so you may still wish a DSL installer visit, if that option is available to you.
[Update] You may also be looking at the offerings for a business quality DSL line. At this time (Oct 2005) DSL prices have dropped to make DSL more competitive with Cable.
(taken from here)
Thanks to the members of the Broadband photo forum for these images
TTL or Time to Live refers to how many routers your packet can go through before it expires. Usually a packet finds its home in less than 32 hops, but 64-128 is a good default.Q: Then why is the TTL 64 when I ping my host computer but 49 when I ping some other site?
Every time a packet passes through a router the TTL number is one less than before. If this counter didn't exist the internet as we know it could be at 100% bandwidth bouncing these packets back and forth that would never find a home if the destination is unreachable. That would make the internet unusable.----
Thanks to BlitzenZeus for these answers.
good and thanks
Thanks a Lot It Was HelpFull
The TCP Receive Window has a default value of only about 8K bytes in Windows 95/98/NT, and about 16K bytes in Windows Me/2000/XP, which is adequate for relatively slow dialup modems and for high-speed networks with relatively low latency (e.g., less than 20 milliseconds). Increasing the TCP Receive Window above the default settings (e.g., to 32-64K) can substantially improve throughput on high-speed Cable Modem or DSL connections where there is higher latency (e.g., 100-200 milliseconds), as is often the case on the Internet, particularly over long network paths. (Increasing the TCP Receive Window will usually not have an adverse effect on other connections.)
For example, let's consider the case of downloading a file at 150 kilobytes per second from a remote server over a typical 1.5Mbps broadband connection. A default TCP Receive Window of 8K bytes will be filled in only about 53 milliseconds, which is often shorter than the round-trip latency on the Internet. When the window is full, the sender has to stop sending until an acknowledgment of the data that was received comes back from the recipient. With a TCP Receive Window of 32K bytes, the sender can continue for as long as 217 milliseconds without an acknowledgment, which should permit uninterrupted data flow even when latency is 100-200 milliseconds or more. (With a TCP Receive Window of 64K bytes, the sender can continue for as long as 450 milliseconds.)
The moral of the story is this: Slower download speeds on lower latency need a smaller (say, 10K) RWIN. High speed connections on long latency networks may need a much larger RWIN (say, 32000). Here below are some suggested settings to try for broadband connections, based on latency and rated download speed.
Low latency (<40ms)
500 Kbps --- RWIN 5000
1000 Kbps -- RWIN 10000
1500 Kbps -- RWIN 15000
2000 Kbps -- RWIN 20000
2500 Kbps -- RWIN 25000
Medium latency (<90ms)
500 Kbps --- RWIN 10000
1000 Kbps -- RWIN 15000
1500 Kbps -- RWIN 20000
2000 Kbps -- RWIN 25000
2500 Kbps -- RWIN 30000
Long latency (<150ms)
500 Kbps --- RWIN 15000
1000 Kbps -- RWIN 20000
1500 Kbps -- RWIN 25000
2000 Kbps -- RWIN 30000
2500 Kbps -- RWIN 35000
Adjusting your RWIN will not affect your rated line speed, it only allows for transfers to be of maximum efficiency. Some users should note that even if they signed up for 1.5Mbps max service they may be capped at lowers speeds such as 768Kbps or 384Kbps, depending on individual line conditions. Your RWIN has no effect (well, a negligible effect, anyway) on your TTL, MTU or latency! A well tuned RWIN can, however, greatly improve transfer speeds by increasing data transfer efficiency.
No mention in this important FAQ of how and where to access the RWIN window and its fields to make the damn change!
Logically, you would also like to get as much data on each transfer as they are willing to send, so you would want select an MTU of 1500 (if your ISP supports it). This would ensure the best possible transfers. If you are using router PPPoE, then your max MTU as allowed by your ISPs and the PPPoE protocol is 1492. Other versions of PPPoE have maximum MTUs of 1400-1492(1438 max for AOL Plus, but 1400 is a better setting for AOL.) You may need to check with your ISP to find out what the maximum MTU is for your network. Setting an MTU that is too small or too great can have extremely deleterious effects on your broadband preformance. Altering your MTU will not affect your latency or TTL. Adjusting the MTU to its ideal setting creates more efficient transfers and thus better overall performance. A well-tweaked system can have high speed, fewer errors and better transfer efficiency.
http://www.mynetwatchman.com/kb/ADSL/pppoemtu.htm An MTU of 1454 may provide better throughput than 1492 with PPPoE.
Also read About DSL for lots more information