[AusNOG] MLPPP experiences

[Joseph Goldman]

Hi list,

  Recently found the need to start experimenting with MLPPP for some 
upcoming deployments.

  Our LAC has been capable for some time we've just never really had a 
need for it.

  In our office, we have a Telstra ADSL and an Optus ULL line. 
Ultimately, there is a 10ms difference between them back to our LAC 
(one's at ~30 the other at ~40). We achieved a MLPPP connection to our 
LAC but what we found were less then stellar results. The 2 lines, by 
themselves, sync and run at around 11mbit/800kbit, but when being used 
in MLPPP we found we couldn't achieve above 10mbit.

  Monitoring the interfaces we could see that it was successfully 
sharing that 10mbit across both links equally, we just couldn't max out 
the lot.

  In your experiences, does the difference in latency that large cause 
big problems (i.e. packets ultimately transmitting out of order and a 
lot of corrections to be done) or are there other caveats of MLPPP i 
should be aware of that could cause similar issues?

  For reference sake, our test LAC is a Cisco 7206 and the test CPE is a 
Mikrotik RouterOS device (using 2 ADSL Modems in bridge into an ethernet 
port each).

Thanks,
Joe