[SR-Users] IPv4 / v6 request to global parameter "TOS"

[Klaus Feichtinger]

Hello list,

in a bridging scenario with kamailio 3.3.4 and rtpproxy 1.2.1 for 
bridging signalling and media from an IPv4 to an IPv6 network and vice 
versa I found that the TOS value, which is set in kamailio.cfg, is used 
for IPv4 packets only. IPv6 packets have the traffic class value set to 
the default value 0x0. In other words: kamailio doesn´t use this 
variable for IPv6 packets. In the cookbook 
(http://www.kamailio.org/wiki/cookbooks/3.3.x/core#tos) I haven´t found 
any hint that it _is_ limited to IPv4 only ("...for the sent IP packages").

I know that the name "tos" may be misleading, as the original definition 
was outdated by dscp+ecn, but it was/is working fine now. However, as 
IPv6 is using dscp+ecn, too, I wonder if the tos variable should support 
IPv6 packets, too.

Could anybody give me a hint? Is there maybe an alternative way to 
prioritise SIP in IPv6 with kamailio?

Thanks in advance,
Klaus Feichtinger