[cisco-voip] Paetec SIP Trunk required Full Duplex Stream for Music on Hold to work

Wes Sisk wsisk at cisco.com
Thu Apr 28 10:53:08 EDT 2011


Jason,

Thanks for sharing.

Some inspection devices do not like half duplex streams. MoH is 
inherently an Rx only stream, there is no real reason for a Tx stream.  
With Rx only CM only signals audio in one direction.  Some inspection 
devices view this negatively.  The service parameter has CM signal over 
the network to open a bidirectional stream even though the Tx stream is 
not used.  RTP fully allows half duplex. Some products and individuals 
just get a bit over zealous in inspection.

Regards,
Wes

On 4/28/2011 10:22 AM, Jason Aarons (AM) wrote:
>
> This does appear to be a Paetec SIP provider firewall issue that is 
> fixed by setting “Full Duplex Stream” in CCMAdmin > Service Parameters 
> > Advanced Parameters.
>
> Paetec is delivering SIP service inside the MPLS cloud for multiple 
> sites (each site has it’s own CUBE 2951 15.1.3T1, no ip cef) running 
> on centralized CallManager 7.1(5).
>
> I toggled Full Duplex Stream to False and the far end doesn’t get MoH. 
> Set it to True and it works. Default is False.
>
> Via CallManager packet capture we saw MoH to gateway, at gateway via 
> Embedded Packet Capture we see exported .pcap file showing stream to 
> Paetec IP and heard it playout via Wireshark. Already tried disabling 
> ip cef earlier, but the Full Duplex Stream fixed it. So I’m guessing 
> it’s something with Paetec’s firewall.
>
>
>
> ------------------------------------------------------------------------
>
> *Disclaimer: This e-mail communication and any attachments may contain 
> confidential and privileged information and is for use by the 
> designated addressee(s) named above only. If you are not the intended 
> addressee, you are hereby notified that you have received this 
> communication in error and that any use or reproduction of this email 
> or its contents is strictly prohibited and may be unlawful. If you 
> have received this communication in error, please notify us 
> immediately by replying to this message and deleting it from your 
> computer. Thank you. *
>
> **
>
>
> _______________________________________________
> cisco-voip mailing list
> cisco-voip at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-voip
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://puck.nether.net/pipermail/cisco-voip/attachments/20110428/bc797a16/attachment.html>


More information about the cisco-voip mailing list