H.248

Also known as Megaco, H.248 is a protocol for controlling media gateways via a softswitch or a media gateway controller.

TelcoBridges and H.248

A version of Toolpack that supports the H.248 protocol is currently in development and is targeted for release in the first half of 2010. Further details will be provided at that time.

As indicated in the diagram below, the H.248 stack will be implemented as a module in the media gateway application residing on the application server. It will communicate with the various Toolpack classes (CAFClass, CMC Library, CMC Class) as required via a new Media Leg API. In turn, the media gateway application will communicate with the softswitch / media gateway controller via the H.248 protocol.

Planned H.248 package support

Support for the following packages is currently in scope.

• H.248.1
  • Protocol v2
  • IPSec connection support
  • Support UDP (2944 or user-defined)

• H.248.1 - Basic packages
  • Generic
  • Base Root
  • Tone generator (for extension purposes only)
  • Tone detection (for extension purposes only)
  • Basic DTMF generation
  • DTMF detection
  • Basic continuity package
  • Network package
  • RTP package
  • TDM Circuit package

• H.248.2 Facsimile, text conversation and call discrimination packages
  • Fax/TextPhone/Modem tones detection (fax and data only)
  • Call type discrimination package (fax and data only)

• H.248.4 Transport over Stream Control Transmission Protocol (SCTP)

• H.248.7 Generic announcement package
  • Generic announcement package

• H.248.10 Media gateway resource congestion handling package
  • Congestion handling package

• H.248.11 Media gateway overload control package
  • Overload control package

• H.248.13 Quality alert ceasing package
  • Quality alert ceasing package

• H.248.14 Inactivity timer package
  • Inactivity timer package

Additional details

• Support for text mode only

References

• Wikipedia article