I have discovered a possible problem with the 7931 phone load 8-4-2S. I know that it appears to be a phone load and not an IOS or CME bug because I am able to make calls with Re-INVITEs and very similar signaling without a problem with the Cisco IP Communicator softphone connected to the same UC520 unit.
Here is what is occurring in the problem calls, and also in some of the good calls that I made with the Cisco IP Communicator softphone:
- An INVITE message is sent to the UC520 unit, with G.729 codec first, followed by G.711 mu-law, and then G.711 A-law last.
- A re-INVITE message is sent to the UC520 unit, with G.711 mu-law first, followed by G.711 A-law, and the G.729 codec last.
- The problem calls will hear one-way audio, but good calls that I have made do not experience this one-way audio problem.
Has anyone else experienced this problem with the 8-4-2S phone load? Has anyone experienced the problem described here, but with other 7900 series phones with the 8-4-2S load?