Re: [BEHAVE] BoF request: STUN Control Usage

On 6/8/07, Dan Wing <dwing@cisco.com> wrote:
>
> > Any idea how many of the deployed SIP servers use UDP?
>
> There is some information from SIPit 20,
> https://www.sipit.net/SIPit20_Summary but of course that
> lacks market share information.

Interesting.  So it looks like most implementations support both.  I wonder
how many of those actually use the UDP implementation over the TCP in terms
of what clients actually connect with.  I know I wouldn't, but I wonder.

> Additionally, under high traffic rates from a single IP
> address (such as a bunch of SIP clients behind a single NAPT),
> draft-heffner-frag-harmful describes problems with reassembly
> which I doubt are sufficiently appreciated by those running
> SIP over UDP.

I would think there would be many issues along these lines.  It has to be
one of the thorniest parts of any implementation in any case.

> To summarize, I believe you're saying if UDP keepalives create
> too much load on your server or network, just use TCP.

Basically.  Put a slightly different way, if no one's using UDP in practice
anyway, then the TCP keep alive mechanism doesn't seem too onerous.  There
unfortunately seems to be little way to get a solid answer to that question,
though, so I'm not sure where to go with it.

Thanks.

-Adam