TCP optimization for GPRS/3G?

[JacoV]

Hi There,

I have to admit, I am quite a novice if it comes to networks and to the Windows OS.

I am just curious, does the TCP parameters (Sliding Window size, etc.) on Windows change when I use a GPRS/3G connection instead of a normal 10 Mb/s / 100Mb/s Network card?

If not, are there ways to optimise TCP for GPRS/3G networks. If one could, should one prefer a large Sliding Window size, or a small one? I see that the buffers also play a role, but if I have to guess, a large buffer size is necessary when you have a very fast link - not like GPRS/3G, and a large Sliding Window Size.

(I am using a GPRS module to connect to the network. I set it up as a normal Dail-up modem on the Windows OS.)

Any suggestions would be greatly appreciated,
Jaco

 

[WireFree]

I am just curious, does the TCP parameters (Sliding Window size, etc.) on Windows change when I use a GPRS/3G connection instead of a normal 10 Mb/s / 100Mb/s Network card?

No.

If not, are there ways to optimise TCP for GPRS/3G networks. If one could, should one prefer a large Sliding Window size, or a small one? I see that the buffers also play a role, but if I have to guess, a large buffer size is necessary when you have a very fast link - not like GPRS/3G, and a large Sliding Window Size.

That depends. The Linux 2.6 kernel has some TCP algorithms for wireless networks. You can read the ietf RFCs if you want to know more. I can't help you with Windows, however Vista has a better TCP stack than it's predecessors.

(I am using a GPRS module to connect to the network. I set it up as a normal Dail-up modem on the Windows OS.)

You are the first person I've come across who has connected a GPRS module to his Windows computer - that's hardcore. Most people use a modem, data card or phone.


WireFree

 

[vodacom3g]

You are the first person I've come across who has connected a GPRS module to his Windows computer - that's hardcore. Most people use a modem, data card or phone.

Probably the same thing.

@JacoV, I'd play around with the TCP window size. The more reliable the connection, the larger it can be. A clever stack will manage it based on QoS, but you might need to write this.

 

[Csnoopy]

Hi There,

I have to admit, I am quite a novice if it comes to networks and to the Windows OS.

I am just curious, does the TCP parameters (Sliding Window size, etc.) on Windows change when I use a GPRS/3G connection instead of a normal 10 Mb/s / 100Mb/s Network card?

If not, are there ways to optimise TCP for GPRS/3G networks. If one could, should one prefer a large Sliding Window size, or a small one? I see that the buffers also play a role, but if I have to guess, a large buffer size is necessary when you have a very fast link - not like GPRS/3G, and a large Sliding Window Size.

(I am using a GPRS module to connect to the network. I set it up as a normal Dail-up modem on the Windows OS.)

Any suggestions would be greatly appreciated,
Jaco

Here is a How To, plus links to utilities. I suggest you download TCPoptimiser.

http://mobilesociety.typepad.com/mobile_life/2006/10/tcp_settings_fo.html

 

[AirWolf]

Probably the same thing.

@JacoV, I'd play around with the TCP window size. The more reliable the connection, the larger it can be. A clever stack will manage it based on QoS, but you might need to write this.

http://www.gsm-modem.de/gprs-module.html

Does a GPRS module plug directly onto your motherboard?

 

[Csnoopy]

http://www.gsm-modem.de/gprs-module.html

Does a GPRS module plug directly onto your motherboard?

According to the specs it connects to the PC serial/comm port.

 

[AirWolf]

According to the specs it connects to the PC serial/comm port.

Any idea on why it is called a module and not a modem?

 

[vodacom3g]

Any idea on why it is called a module and not a modem?

If it MOdulates and DEModulates, it's a modem, as this device obviously is.

BTW, VMC 9 will also optimise your TCP setup.