[asterisk-users] SIP and FW settings

[SIP]

Michael wrote:
> On Tue, 14 Apr 2009 20:47:29 you wrote:
>   
>> Hi michael,
>>
>> you should open both tcp,udp 5060,5061 too and as you mentioned between
>> 10000-20000.
>>     
>
> AFAIK 5061 TCP is for TLS SIP which isn't used much yet?
>
> Is TCP the default for 5060, with UDP as fallback, or is this provider 
> dependent? 
>
> Michael
>
>   
That's provider dependent. MOST SIP is done with UDP. Some people use
TCP to get past firewalls or try and alleviate NAT issues, but it's
non-standard and falls into the category of 'complete hack' where SIP is
concerned. TCP is allowed via the RFC, I believe (I vaguely remember a
transport=tcp setting somewhere in a header field), but whether or not
it's supported by the provider or software varies widely.  Microsoft
uses only TCP in their communicator product, I think. Some clients will
let you choose TCP or UDP.  But for the most part, when dealing with a
default asterisk install and your own phones/softphones, you shouldn't
need to worry about TCP.

N.