H.225.0

H.225.0 is a member of the H.323 family of protocols.

The main objective of H.225.0 is the definition of messages:
* "Call Signaling"': establish, control and end an H.323 call. The call signaling of H.225.0 is based on the call setup procedures for ISDN, Recommendation Q.931.

* RAS Signaling Function: perform registration, admission, bandwidth changes, status and disengage procedures between endpoints and an H.323 Gatekeeper. The RAS signaling function uses a separate channel (RAS channel). This set of messages is called Registration, Admission and Status (RAS).

The Message Encoding is performed by utilizing Q.931 User-to-User information elements to convey H.225 messages. The messages themselves are encoded according to the Packed Encoding Rules (PER) of ASN.1.

The structure of H.225 follows the Q.931 standard as seen in the table below.

External links

General Information
* [http://www.itu.int/rec/T-REC-H.225.0/en ITU-T H.225 Recommendation]

Products
* [http://www.radcom.com/Products.aspx?BoneId=675 RADCOM H.323 Tester including H.225 Protocol]