CODEC Selection

Created by Kelly Evans, Modified on Wed, 4 Jun at 10:56 AM by Kelly Evans

The Peeredge Orchestrator supports the following audio codecs.

G.711ulaw	G.722	G.726-32	G.729.1	L16	iLBC
G.711alaw	G.723	G.726-40	G.729D	L20	PCMA-WB
G.729	G.726-16	G.728	GSM	L24	PCMU-WB
G.719	G.726-24	G.729E	L8	LPC	Speex

By default, the Peeredge Orchestrator adds all codecs in the SIP Invite received on the origination call leg to the SIP Invite sent on the termination call leg. The Peeredge Orchestrator can be configured to filter out codecs offered in the SIP Invite and/or add additional codecs in the SIP Invite w/SDP offer to the customer SBC/PBX. If additional codecs are added to the termination leg SIP Invite, transcoding must be enabled.

Recommendations

Since most PSTN carriers only support the G.711ulaw, G.711alaw, and the G.729 codecs, 46 Labs STRONGLY RECOMMENDS only including these codecs in the SIP Invite w/SDP to the Peeredge Orchestrator. Our testing with several enterprise SBC and PBX systems shows there are often hidden design challenges in complex call flows when using codecs not supported by upstream carriers.

When voice quality is the primary design consideration, 46 Labs recommends using the G.711 codec.

When minimizing network bandwidth usage is the primary design consideration, the G.729 codec can be configured as the preferred codec.

For cloud based PBXs (i.e. Microsoft Teams, Cisco Webex, etc.), 46 Labs recommends using the G.711 codec. Network bandwidth usage is generally not a concern, and it is a higher quality codec than G.729.

The Peeredge SBC does not support video codecs. Video codecs should not be included in the SDP of any SIP messages sent to the Peeredge SBC.