Protocol Interworking on Cisco UBE Gateways
Cisco UBE can interwork signaling protocols, agnate to a proxy. This affection can be used
for two scenarios:
■ Interworking amid the aforementioned signaling protocol: A Cisco UBE that is interworking
between the aforementioned signaling agreement (for archetype H.323-to-H.323) can be used
to break interoperability issues amid two accessories accepting altered capabilities.
Because Cisco UBE builds two alarm legs to anniversary peer, it can interwork amid those
two alarm legs. For example, Cisco Unified Communications Manager Express uses
H.450, a subset of H.323, for alarm transfers and alarm forwarding. Back connected
directly to a Cisco Unified Communications Manager, which does not support
H.450, alarm forwarding and transfers ability advance to hair-pinned calls and suboptimal
WAN usage. A Cisco UBE at the Cisco Unified Communications Manager armpit can
be acclimated to break these issues.
Figure 9-2 Cisco UBEs in Enterprise Environments
■ Interworking amid altered signaling protocols: Cisco UBE can interconnect
dial aeon that use altered signaling protocols, such as a SIP and an H.323 punch peer.
This allows for greater adaptability back deploying an IP communications network.
Both H.323 and SIP abutment two methods of alarm setups. H.323 uses fast alpha and slow
start, admitting SIP uses aboriginal action and delayed offer. Both H.323 fast alpha and SIP early
offer are acclimated to set up the media approach faster than during accepted alarm setup.
Problems appear back one endpoint expects an H.323 apathetic alpha or SIP delayed action and
the added endpoint uses H.323 fast alpha or SIP aboriginal offer.
When interworking signaling protocols, a Cisco UBE supports the afterward combinations,
as illustrated in Figure 9-3:
■ H.323-to-H.323: An Cisco UBE absolutely supports fast alpha with apathetic alpha interworking
in all directions.
■ H.323-to-SIP: H.323 fast alpha to SIP aboriginal action interworking is absolutely supported. An
H.323 apathetic alpha to an SIP delayed action is accurate alone for entering H.323 to outbound
SIP calls.
■ SIP-to-SIP: Aboriginal action and delayed action are absolutely accurate on Cisco UBE in all
directions.
Chapter 9: Establishing a Connection with an Internet Telephony Service Provider 527
Cisco UCME
H.323 Video
Video Interworking for
External Video Clients
Interworking and CAC Amid Cisco
Unified Communications Manager
Express and Cisco Unified
Communications Manager
CAC Amid Cisco
Unified Communications
Manager
Protocol
Interworking
H.323 Video
Secure VoIP
Interworking
LAN/WAN
SIP
Carrier
Internet
DMZ
GK
CUBE
GK=Gatekeeper
CUBE=Cisco UBE
H.323-to-H.323 In Leg Out Leg Support
Fast Alpha Fast Alpha Bidirectional
Slow Alpha Apathetic Alpha Bidirectional
Fast Alpha Apathetic Alpha BidirectionalH.323-to-SIP
SIP-to-SIP
Slow Alpha Delayed Action Unidirectional
Fast Alpha Aboriginal Action Bidirectional
In Leg Out Leg Support
Delayed Action Delayed Action Bidirectional
Early Action Aboriginal Action Bidirectional
Figure 9-3 Agreement Interworking Abutment on Cisco UBEs