2-7
Cisco Multiservice Packet Network Solution Overview
OL-3025-01
Chapter 2 Solution Components
Media Gateways
The Media Gateway Control Protocol (MGCP) provides the call control for the setup and teardown of
calls. The VISM Software Release 2.1 supports MGCP Version 0.1, and the VISM Software Release 3.0
supports MGCP Version 1.0.
The Simple Gateway Control Protocol (SGCP) and Simple Resource Control Protocol (SRCP) are used
by the call agent to verify that the VISM is operational, and for auditing the status of the lines. Both the
VISM classic and VISM-PR cards support SGCP Version 1.1 and SRCP Version 1.0. Figure 2-3 shows
the control traffic protocols in a sample configuration with all components in the same location.
Figure 2-3 Control Traffic between the VISM and iMSS Call Agent
Voice Bearer Traffic
The voice traffic is first formatted into a Real-Time Transport Protocol (RTP) packet, then encapsulated
in a UDP and then an IP packet, and then converted to AAL-5 ATM cells (that comply to RFC 1483) for
transmission to the network. RTP is used to allow time-stamping of the voice samples to permit
dejittering of samples transmitted to the destination TDM line. Figure 2-4 shows the voice bearer
protocols in a sample configuration with VISMs connected to edge routers dedicated to voice traffic.
Figure 2-4 Voice Bearer Traffic
Physical Layout
See Figure 2-5 for a sample physical configuration for a voice-only deployment of MGXs with VISMs
as the media gateways. The call agent for this configuration is the iMSS-4040 providing TDM PRI and
V5.2 connectivity, running in an enhanced configuration. The line cards require a TDM Switching matrix
card on the Optical Peripheral Module (OPM) of the iMSS call agent, and an Add/Drop Multiplexer
(ADM)—either third party or Italtel—to handle the E1 lines for the iMSS-4040, and to handle the PRI
and V5.2 connections. In this sample configuration, the ADM is also required to handle the
communication with the VISM over the E1 rather than STM-1 connection.
V
V
V
MGCP/SRCP
UDP
IP
Ethernet
MGCP/SRCP
UDP
IP
Ethernet
MGCP/SRCP
UDP
IP
ATM AAL5
OC-3
Cisco router
72722
Cisco MGX
with VISM
Cisco Catalyst
switch
Italtel iMSS
call agent
V
V
V
Voice payload
RTP
UDP
IP
ATM AAL5
OC-3
Voice payload
RTP
UDP
IP
MPLS
Voice payload
RTP
UDP
IP
ATM AAL5
OC-3
Cisco router Cisco router
V
V
V
72723
Cisco MGX
with VISM
Cisco MGX
with VISM
(403 paginas)
(60 paginas)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Comentarios a estos manuales