Also known as Megaco, H.248 is a protocol for controlling media gateways via a softswitch/Media Gateway Controller (MGC).

TelcoBridges and H.248

Toolpack now supports the H.248 protocol.

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

H.248 schematic.jpg

H.248 package support

Toolpack supports the following packages.

  • 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
    • Call Progress Tones Generator (Ringing, Busy, Congestion and Warning tones supported)
    • Basic continuity package
    • Network package
    • RTP package
    • TDM Circuit package (only echo-cancellation)

  • 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)
    • IP Fax (Event: Fax Connection Change - end of fax session, call terminating)

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

  • H.248.7 Generic announcement package
    • Generic announcement package (Fix Announcement play only)

  • 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

  • H.248.16 Enhanced digit collection packages and procedures
    • Extended DTMF detection package
    • Enhanced DTMF detection package

  • H.248.23 Enhanced alerting packages
    • Enhanced alerting package
    • Analogue Display Signalling package

  • H.248.25 Basic CAS packages
    • Basic CAS package
    • Basic CAS addressing

  • H.248.27 Supplemental tones packages
    • Carrier tones generation package
    • Diagnostic tones generation package

  • H.248.28 International CAS packages
    • International CAS
    • CAS blocking

  • H.248.29 International CAS compelled register signaling packages
    • Annex A.1 only in 'enbloc' compelled mode (International CAS Compelled package - No digitmap control: Digitmaps are preconfigured on MG)

  • H.248.36 Hanging Termination Detection package
    • Hanging Termination Detection package

  • Q.1950 packages
    • Basic call progress tones generator package
    • Expanded call progress tones generator package
    • Basic services tones generator package

Additional details

  • Support for text mode only