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M1ND1355

join:2010-06-14
Albert Lea, MN

Upload speed varies because router?

My cousin has DSl through SkyBeam. His download is 4mbs and upload is 1.9mbs, when he is wired though his modem only. When he hooks up his wireless router his download stays the same but upload drops to 0.4 mbs which is a huge fall. Cisco and skybeam are not sure of the problem just thought i could maybe get some input here. thanks



grohgreg
Dunno. Ask The Chief

join:2001-07-05
Dawson Springs, KY

By what means is he determining throughput speed?

//greg//


alhanson

join:2006-01-29
Barneveld, WI
reply to M1ND1355

What you have done is put a router between your satellite modem and your computer. Your computer doesn’t know what the [MTU] "Maximum Transmit Unite" is for the Satellite connection. Most operating systems calculate this Unite automatically. The reason you get the higher throughput when connecting the computer directly to the modem it the modem can tell the computer what the [MTU] is for the satellite connection. The OS can figure out it [MTU] in less then 1ms from the router. However, if you break this link, the OS has to got out over the satellite connection to the [NOC] “Network Operations Center” and calculate the [MTU] unit it self. If you add satellite latency into this mix I think you can begin to see the problem.

The way you set the [MTU] for your satellite connection manually in the router is the same method the OS uses. The [MTU] is represented by a number between 1 and 1500. It is the amount data the can be encapsulated in to a packet the can be sent to and from the satellite.

Open up your router to the page where you set the [MTU]. Type a low number, like 1400, in to the text box. Save the router configuration. Next open the Command Prompt ping something out on the Internet like Google. If you get a reply from Google reopen your router and add 2 to 1400 = 1402 and save the router configuration. Open up the Command Prompt and ping to see if you still have a connection. Keep doing this until the connection times out. Back off the increment of 2 in your router configuration {and that is your [MTU] for you satellite connection}. Now the Computer can Query the Router and find out what the [MTU] is for the satellite connection is in less than 1ms.

In conclusion: the [MTU] for a given satellite is written is Stone.



grohgreg
Dunno. Ask The Chief

join:2001-07-05
Dawson Springs, KY
reply to M1ND1355

Actually Al, this isn't even satellite-related. The topic should have been moved months ago. SkyBeam is WiFi.

//greg//


alhanson

join:2006-01-29
Barneveld, WI

Greg,

What I have done here is back engineer a “denial of service attack” on my Wildblue satellite connection. Not only does it apply to Satellite but also Wi-Fi. The attack came from China. It is not my intent to teach people how to exploded weakness. But rather come up with solution for the problems. This above solution could help a lot of people with satellite and WiFi. This all begin a few years back when the Deli Lama’s supporters got Wildblue satellite. We all live in the same county in Wisconsin where three satellite beams overlap. The exploit is to use the [MTU] of the victim’s connection having his OS continuously Query and reset the [MTU]. Some cellular WiFi has latency close to, if not as high, as satellite.

I think the Forum should expand it scope and see not just trees but also the forest. Talk about Security, Networking and how thing are interconnected. A modem is a modem. A router is a router. And a Lan is a Lan. The protocols for the media and devices are standards. If the weren’t nothing would work would it!