huge ping reply time with iprohcserver/client

Asked by intizar on 2013-10-09

Hello ,

i see huge ping reply time when even running iprohc server and client both on Lan . ping reply /response time from client to server is about 1200 to 1400 mili secs . what's the hardware requirement for iprohc client and server , without iprohc server /client i can ping both way with reply time of 1or 2 ms .

thanks .

Question information

Language:
English Edit question
Status:
Solved
For:
rohc Edit question
Assignee:
No assignee Edit question
Solved by:
Didier Barvaux
Solved:
2013-10-09
Last query:
2013-10-09
Last reply:
2013-10-09

This question was reopened

Hello,

As stated on [1], the IP/ROHC tunnel implements packing. So, it waits a little bit for additional ROHC packets before sending them altogether. If no additional packets come, the packet is sent alone after some time.

This behavior works great for traffic with many small packets such as VoIP. It does not work well for scarse traffic such as a single ping. Try sending ICMP packets quicker with a command such as: ping -i 0.2 <ipaddress> . It should give you better RTT.

You may also change the "packing" parameter in the configuration file of the IP/ROHC server to increase/decrease the number of packets that are packed together.

Regards,
Didier

[1] http://rohc-lib.org/wiki/doku.php?id=iprohc-overview

intizar (intizar57) said : #2

Thanks Didier Barvaux, that solved my question.

intizar (intizar57) said : #3

setting packing to 1 got me realtime RTT , but i think this would affect compression right ? there will be less compression if we set very low packing , the higher the better ?

kind regards .

intizar (intizar57) said : #4

Thanks Didier Barvaux, that solved my question.

> setting packing to 1 got me realtime RTT , but i think this would
> affect compression right ? there will be less compression if we
> set very low packing , the higher the better ?

Yes, the higher the better. But the increase is not linear, so above some value more packing results in very small additional gain. And, as you experienced, the more packing you configure, the more latency is high if traffic is scarce.

Didier