A Cisco IP Phone 7841 that is registered to a Cisco Unified Communications Manager with...

The SDP offer includes the following line of text:

M=audio 498181 RTP/AVP 0 8 97

This line of text indicates that the following codecs are available:

0: G.711ulaw

8: G.711alaw

97: iLBC

The Cisco IP Phone 7841 is registered to a Cisco Unified Communications Manager with default configuration. This means that the phone will negotiate the G.711ulaw codec.

The G.711ulaw codec is a standard codec that is used for voice communication. It is a low-bandwidth codec that provides good quality.

The iLBC codec is a newer codec that is designed for use in low-bandwidth environments. It provides good quality, but it is not as widely supported as the G.711ulaw codec.

The G.722 codec is a high-quality codec that is used for voice communication. It provides excellent quality, but it requires more bandwidth than the G.711ulaw codec.