H225 RAS Messages

by | Mar 4, 2010 | H.323, IOS, Lab, Non classé, Written Theory | 0 comments

Here are the different messages used by the H225 RAS signaling which can occur between endpoints and GK.

  • Gatekeeper Discovery : used by endpoints to register

    • GRQ : Gatekeeper Request
    • GCF : Gatekeeper Confirm
    • GRJ: Gatekeeper Reject
  • Registration/Unregistration : used by endpoints to register or unregister their address and their zone withtin the GK.

    • RRQ : Registration Request
    • RCF : Registration Confirm
    • RRJ : Registration Reject

    • URQ : Unregistration Request
    • UCF : Unregistration Confirm
    • URJ : Unregistration Reject
  • Admission Control : These messages are used for all admission control and bandwidth management

    • ARQ : Admission Request
    • ACF : Admission Confirm
    • ARJ : Admission Reject
  • Bandwidth Control : these messages are used if you want to change the amount of bandwidth during a call

    • BRQ : Bandwidth Request
    • BCF : Bandwidth Confirm
    • BRJ : Bandwidth Reject
  • Endpoint Location : These messages are used to retrieve contact information ( also with Directory GK)

    • LRQ : Location Request
    • LCF : Location Confirm
    • LRJ : Location Reject
  • Status Information : They are used to retrieve a status information

    • IRQ : Information Request
    • IRR : Information Response Request

H225 call control signaling is on TCP/1720 and uses Q931 messages to establish, maintain and tear down calls. these messages are

  • Setup
  • Setup Acknowledge
  • Call Proceeding
  • Progress Alerting
  • Connect
  • User Information
  • Release Complete
  • Status Inquiry
  • Status
  • Information
  • Notify

So in general , here is the following reminder: While h225 call control signaling can be used for call setup, H245 must be used to determine a master/slave relationship, exchange terminal capabilities, logical channel signaling and DTMF relay.