ZyXEL Communications ISG50 User Manual

Chapter 30 Outbound Trunk Group

ISG50 User’s Guide

Use this screen to select which auto-attendant should be used with this outbound line group. See 

 for information on configuring auto-attendants. You can also configure 

Codec Setting

Select the type of voice coder/decoder (codec) that you want this extension to use when 
communicating with the ISG50. The following codecs (shown in highest quality to lowest 
quality order) are supported by the ISG50:

•

G.711 alaw (typically used in Europe)

•

G.711 ulaw (typically used in North America and Japan)

•

G.729 

•

G.722  

•

G.723.1 

•

G.726 

See 

 for more information.

When two SIP devices start a SIP session, they must agree on a codec.

If these SIP extensions are assigned to videophones, you must specify the video codecs 
used for video calls. The ISG50 allows the following video codecs to pass through:

•

H.261 

•

H.263  

•

H.264 

•

MP4 

See 

 for more information on video codecs.

Codec Pool

This column indicates the codec types not used for these extensions. You can add a codec 
type to be used for these extensions by highlighting it and clicking the Right button. 

Codec List

This column indicates the codec types used by these extensions. You can organize the 
priority of the codecs by highlighting it and clicking the Up or Down buttons to move the 
codec higher or lower in priority. The SIP extensions attempt to use the higher priority 
codecs first and try the lower priority codecs next. You can remove a codec type from 
being used from these extension by highlighting it and clicking the Left button. 

Apply

Click this to save your changes.

Cancel

Click this to set every field in this screen to its last-saved value.

SIP Trunk Add/Edit (continued)