Cisco Gateways
Gateways are devices used to connect your IP telephony infrastructure to the
Public Switched Telephone Network (PSTN) or to legacy PBX systems. Cisco’s
product line currently includes over 20 different gateway products, each supporting
the various types of gateway protocols. Currently there are three different
types of gateways supported by the Cisco IP telephony solution:
Skinny Gateway Protocol
H.323
MGCP
The Skinny Gateway Protocol is based on the industry standard SGCP protocol;
however it is only used on the Cisco Gateway product line. In other words,
while SGCP is an open standard, the Skinny Gateway Protocol is a proprietary
standard used by Cisco only. (This reminds one of the Cisco implementation of
High-Level Data Link Control (HDLC)—while HDLC is an industry standard,
Cisco has written extensions into it making its implementation inoperable with
other vendor’s equipment.) Devices that support the Skinny Gateway Protocol
include the DT-24+ and DE-30+ gateways, the Catalyst 4000 WS-X4604-GWY
module, and the Catalyst 6000 WS-X6608-x1 module.
H.323 is an open industry-wide standard. H.323 gateways are most commonly
found in integrated router gateway devices and in communication to
Cisco CallManager. Devices that support H.323 include:VG200, the 1750 router,
the 3810 router, the 2600 router, the 3600 router, the 7200 router, the 5300
access server, and the Catalyst 4000 WS-X4604-GWY module.
Media Gateway Control Protocol is the most recent of the gateway platforms.
MGCP is a Cisco-supported standard and is currently only used in communications
between Cisco CallManager and the VG200 standalone gateway, although
several members of the Cisco product line will support it in the future.This
www.syngress.com
Table 2.1 Continued
IP
Features 7910/7910+SW 7940 7960 7935 SoftPhone
40 Chapter 2 • New World Technologies
group includes the MCS 3810, the 2600 Series routers, the 3600 Series routers,
the Catalyst 4000 WS-X4604-GWY module, and the Catalyst 6000 WS-X6608-
x1 module. As always, consult the Cisco Web site for information regarding new
product support.