Need to make test of IP Header compression PC1<->AR2880_A<->AR2880_B<->PC2. Target is to reduce traffic.
No cRTP statistic, IPHC don't work.
After finished all configuration right, ip connection is working (ping interface successfully), but cRTP don't work.
[interface-serial X/X/X:X]undo shutdown
after you will do like this, you can check that cRTP statistic is now working and Voice traffic is start compressing:
IPHC: RTP/UDP/IP header compression
Compress/Error/Discard/Total: 13599/0/0/13772 (Packets)
Compress/Total: 6620/6796 (Packets)
Send/Save/Total: 188532/249960/438492 (Bytes)
Five-Minute-Miss-Ratio: 74 (Misses/5Mins)
Need to execute additional action.
For test is better use Netmeeting or Huawei VP8020 terminals with H.325 protocol.
Quality of voice in other free software may be not good.