Network Layer; Link Layer; Physical Layer - 3Com MSR 50 Series Configuration Manual

2356 C 136: H.323 C
HAPTER ONFIGURATION
diagnosis as well. These two protocols work together to ensure real-time voice
transmission.
The following figure illustrations the H.323 stack:
Figure 680 H.323 stack
Data
T.126 T.127
T.324
T.124 T.125
T.123
ITU-T RAS is implemented in compliant with the H.323v2 protocol for
communication between gateway and gatekeeper. RAS adopts the
communicating model where the gateway sends requests and the gatekeeper
responds with confirms or rejects as shown in the following table.
Table 89 Major RAS messages
Category
Registration
Unregistration
Management
Admission
Location requests and responses
Signaling
H.245
H.225.0
RAS
TCP

Network layer

Link layer

Physical layer

Message
RRQ (Registration_Request)
RCF (Registration_Confirm)
RRJ (Registration_Reject)
URQ (Unregister_Request)
UCF (Unregister_Confirm)
URJ (Unregister_Reject)
MRQ (Manage_Request)
MCF (Manage_Confirm)
MRJ (Manage_Reject)
ARQ (Admission_Request)
ACF (Admission_Confirm)
ARJ (Admission_Reject)
LRQ (Location_Request)
LCF (Location_Confirm)
LRJ (Location_Reject)
Audio Video
G.711
H.261
G.729
G.723.1
H.263
G.723.A
RTP RTCP
UDP