Hi, AFAIK headers Via, Route and Record-Route can appear multiple times
in a message (not just multiples values in each header), for example:
INVITE sip:asdasdasd SIP/2.0
Via: ,
Via: xxx
Via: xxx
...
I don't find in RFC 3261 which exact headers can appear multiple times
Any header which uses the repeated field separated by comma format can
be repeated either via the comma for by multiple instances of the
header. It spells this out somewhere in 3261.
In theory I think some form of header that doesn't meet that requirement
might also be allowed to be repeated,
