Video issue between polycom and 8950

As migration had started in C Project, customer was using Huawei videophones and Polycom VVX 1500 phones in daily operations. During this interoperability period, customer reported video calls were failing. As we investigated, we found that the failure was occurring in video calls between Huawei and Polycom phones. Video was not being established as shown in the following pictures:

At first, we checked eSpace 8950 phone configuration to make sure video capabilities were correctly configured.

1)     Check video control settings (Call settings > Video Control). Make sure Video and Always send Video is enable.

2)     Check video call settings (Advanced > Media). Check the Encoding Resolution and Maximum Decoding bit rate. In this case, due to bandwidth control, CONAGUA requested 768 K.

With the above parameters checked, we were sure the failure was not in our side. Then, we decided to take a look at Polycom video phones configuration. We requested authorization to do this with the customer.

1)     Access the Polycom phone through web administration (default password 456).

2)     Go to settings and choose Codec Priorities. Select Video.

3)     Check H.264 codec profile. Polycom VVX 1500 model supports the following profile levels: 1, 1b, 1.1, 1.2, 1.3. We found that Polycom phones in C Project were configured with a Profile level of 3.0.

By reviewing product documentation, we realized the profile level was not appropriate. H.264 profile documentation says the standard includes seven sets of capabilities, which are referred to as profiles, targeting specific classes of applications. In the case of Baseline Profile (BP) it is primarily for lower-cost applications with limited computing resources, this profile is used widely in videoconferencing and mobile applications.

We reviewed details of level numbers finding that 1.3 could be appropriate, as shown in the table below:

Levels

Finally, we changed the profile level parameter in Polycom configuration to 1.3 since it matched the one used by huawei eSpace 8950. After this change was made, video was established between Polycom VVX 1500 and Huawei eSpace 8950.