[VOIPSEC] 4G Issue Map: signaling complexity

[Randell Jesup]

"Hadriel Kaplan" <HKaplan at acmepacket.com> writes:
>> SIP compression apparently came about because people felt like they needed
>> to consume less bandwidth over wireless links.  Why that matters when you
>> then send a bunch of RTP packets out seems illogical to me, but I suppose
>> that's why I'm not making wireless handsets.  
>
>Actually, its my understanding it's not so much the bandwidth (although that
>may also matter when you take into account the number of phones in a cell,
>where few are actually in-call but there's still signaling).  But the real
>reasons were serialization delay and bit error rate.  The delay ended up
>creating very long call setup times.  And BER obviously would make it worse
>(not to mention consume more bandwidth).

Also (not having read sipcomp, note) compression should help keep call
setup in one (or less) packets, which is useful, especially for SIP over
UDP (now that packet fragmentation is officially verboten).  Even in
TCP/TLS, less packets means quicker call setup, especially if there's
significant packet loss.

-- 
Randell Jesup, Worldgate (developers of the Ojo videophone), ex-Amiga OS team
rjesup at wgate.com
"The fetters imposed on liberty at home have ever been forged out of the weapons
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