rohc team mailing list archive

[Didier Barvaux <didier@xxxxxxxxxxx>]

Hello,


> Like I said in my previous e-mails on last weeks, I set up a network
> with 2 openflow switches and a ethernet rohc tunnel between them.
> Until now, everything was working fine with icmp (ping) tests. The
> icmp packets are compressed and decompressed through the ROHC tunnel.
> My topology is like the one bellow:
> 
> host 1 <----------> Switch 1 <---------- ROHC tunnel ---------->
> Swich 2 <---------> host 2
> 
> Yesterday, I tried to make a SIP call from host 1 to host 2 and
> unfortunately discovered that the RTP packets don´t pass through the
> Ethernet ROHC tunnel.
>
> [...]
>
> [rohc_comp.c:848 rohc_compress2()] ROHC size = 91 bytes (feedbacks =
> 0, header = 9, payload = 82), output buffer size = 5120

The RTP packet was successfully compressed. It was compressed with the
IP/UDP profile. It would be more efficient with the IP/UDP/RTP profile,
but that's not the cause of your problem.


> sendto failed: No such device or address (6)
> failed to write data on tunnel

It looks like the remote MAC address you specified was not reachable
(does ARP resolves the address fine?) or the Ethernet device changed
since the program started.

For the ARP problem, please check your ARP cache (ip neigh) and/or
check with tcpdump that ARP request/replies are sent/received.

For the Ethernet device, please check the identifier of the interface
before starting the tunnel program and after the error happened: the
command "ip link show dev <device_name>" displays it at the very
beginning of the line. Example with interface named "lan" that got
identifier "2":
  $ ip link show dev lan
  2: lan: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state
  DOWN mode DEFAULT qlen 1000
    link/ether a4:ba:db:d7:a2:16 brd ff:ff:ff:ff:ff:ff


Regards,
Didier