Simulate network/transmission latency

Lowering the speed of the serial lines can significantly increase the delay.

DT

There are a bunch of software tools you can run of a PC etc to sinthesize a delay, but you then would need serial interfaces card or to use ethernet

you can find these by searching google.

i prefer dedicated hardware to do this since that way it doesnt vanish from the lab when i dont use it for a while :)

i have used a hardware box designed to simulate anything up to satellite delays (much cheaper than a satellite link!) - 1st came across this when we were debugging a satellite link.

i like this one as you can just alter the delay and error rate on the front panel

a few 1000 UK pounds - YMMV - i havent spent money on them for a while.

E1 (G.703) interfaces cost extra.

I just installed NISTNet on a PC with 2 nics and Fedora 4 and it works pretty well. I had to simulate a 140ms delay for a connection from Wisconsin to Czech Republic for app testing. Here is what I did:

TestPC-2611Router-DTE/DCESerialCable-2621Router-NISTNet-CoreNetwork

The serial connection allows me to adjust clock rate to adjust serialization delay. This is important because here is how my results varied:

Real Circuit:

32 byte ping 140ms 1400 byte ping 156ms

Test w/384000 clock rate:

32 byte ping 139ms 1400 byte ping 193ms

Test w/1300000 clock rate:

32 byte ping 139ms 1400 byte ping 153ms