1. Time Division Multiplexing Configuration Guide
  2. Fax Transcoding Support for the Acme Packet 1100

7 Fax Transcoding Support for the Acme Packet 1100

When equipped with the Foreign Exchange Office-Foreign Exchange Subscriber (FXO-FXS) interface and a transcoding Digital Signal Processor (DSP), the Acme Packet 1100 can transcode analog fax calls into the T.38 codec for better transmission quality. When the DSP detects Fax tones, it triggers the Oracle® Enterprise Session Border Controller (E-SBC) to ask the Fax gateway to switch to the T.38 codec. You must configure the E-SBC, by way of codec policies, local policies, and realm configurations, to accept the T.38 codec and let the DSP detect the fax tone to trigger the codec negotiation.

For more information about transcoding, see the ACLI Configuration Guide.

Configure Fax Transcoding for the Acme Packet 1100

The system requires two codec policies, two local policies, and two realms to support fax transcoding.

  • Before you begin, configure one realm that points to the Internet and one realm that points to the Time Division Multiplexing (TDM) interface.

For example, suppose you name the internet-facing codec policy "Remote" and you name the TDM-facing codec policy "TDM." Use the following guidelines for configuration:

Codec policies
  • In the "Remote" codec-policy, set allow-codecs to T.38 PCMU PCMA and set add-codecs-on-egress to T.38OFD.
  • In the "TDM" codec-policy, set allow-codecs to PCMU PCMA and set add-codecs-on-egress to G711FB.
Local Policies
  • In the "Remote" local-policy, set source-realm to remote.
  • In the "TDM" local-policy, set source-realm to tdmRealm.
Realms
  • In the "Remote" realm-config, set identifier to remote, set the codec-policy type, and set codec-manip-in-realm to enabled.
  • In the "TDM" realm-config, set identifier to tdmRealm, set the codec-policy type, and set codec-manip-in-realm to enabled.