Voice quality: SIP vs SCCP


#1

Hi it seems from my testing SCCP voice quality is better than SIP. But since both are signalling protocol, and uses RTP for media transport, why there seems to be a voice quality difference?

I would imagine for call setup SCCP is probably faster but it shouldn’t play a part in determining the voice quality after the call is setup. From what i know codec did played a part in determining the voice quality but not signalling protocol stack.

Any thoughts/comments?

thanks!


#2

What codec are you using? I’m using SCCP at work (Cisco Call Manager Express system) running g.711. My CCME system connects to Asterisk for voicemail and the voice quality in the voicemail is just as good as the quality when I’m on the phone.


#3

one reason that quality could be different is that the code bases for SIP and SCCP are very different, different development teams at Cisco, etc.

some fixes that make their way into SCCP might not make their way into the SIP codebase as fast (if ever?) because Cisco is less incented to encourage SIP deployments.


#4

cisco’s way of punishing those who do not use the one true protocol :laughing:


#5

[quote=“skeagy”]one reason that quality could be different is that the code bases for SIP and SCCP are very different, different development teams at Cisco, etc.

some fixes that make their way into SCCP might not make their way into the SIP codebase as fast (if ever?) because Cisco is less incented to encourage SIP deployments.[/quote]

How does SIP vs SCCP signalling affect the voice quality when that is a function of the codec in use?