If we want to create performant software we'll need to develop over a slow network, so I want to simulate an internet network on my local network. This wish has been lingering at Soops too so here are some pointers.

If we want to simulate developing behind a single ISDN connection accessing a repository accross the Antlatic ocean, we would want to set up something like

64 Kbit bandwith limit
150 ms round trip time
0.1% packet loss

Additionally we could consider

jitter
packet reordering
packet duplication

but I don't expect these to be significant.

netem & iproute

As it happens this functionality is being integrated into the Linux kernel (starting at 2.4.27 and 2.6.8) under the name 'netem' (net emulation). Unfortunately it is in quite a bit of flux right now.

I see that my current Debian/testing installation has a kernel module 'sch_netem' but that the debian package 'iproute' is too old to support it. ('iproute' is a Debianized name, it is known as 'iproute2' on the net).

Excellent internet performance

netem & iproute