Cisco Cisco IOS Software Release 12.2(15)T Guide Du Développeur
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Cisco Gatekeeper External Interface Reference, Version 4.2
Cisco IOS Release 12.2(15)T
Chapter 2 Overview of the Cisco IOS Gatekeeper
Inter-Zone Communication
If an H.323 network deploys inter-zone communication, each terminal should at least have a
fully-qualified e-mail name as its H.323 ID. For example, bob@cisco.com. The domain name of the
e-mail ID should be the same as the configured domain name for the gatekeeper of which it is a member.
As in the previous example, the domain name is cisco.com.
fully-qualified e-mail name as its H.323 ID. For example, bob@cisco.com. The domain name of the
e-mail ID should be the same as the configured domain name for the gatekeeper of which it is a member.
As in the previous example, the domain name is cisco.com.
Inter-Zone Communication
To allow endpoints to communicate between zones, gatekeepers must be able to determine which zone
an endpoint is in and locate the gatekeeper responsible for that zone. If DNS is available, you can
associate a DNS domain name to each gatekeeper.
an endpoint is in and locate the gatekeeper responsible for that zone. If DNS is available, you can
associate a DNS domain name to each gatekeeper.
Accounting Using RADIUS/TACACS+
If you enable AAA on the gatekeeper, the gatekeeper emits an accounting record each time an endpoint
registers or unregisters, or each time a call is admitted or disconnected.
registers or unregisters, or each time a call is admitted or disconnected.
Inter-Zone Routing
There are three types of address destinations used in H.323 calls. The destination can be specified using
either an H.323-ID address (a character string), an E.164 address (a string containing telephone keypad
characters), or an e-mail ID (a character string). The way inter-zone calls are routed by the
Cisco IOS Gatekeeper depends on the type of address being used.
either an H.323-ID address (a character string), an E.164 address (a string containing telephone keypad
characters), or an e-mail ID (a character string). The way inter-zone calls are routed by the
Cisco IOS Gatekeeper depends on the type of address being used.
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When using H.323-ID addresses, inter-zone routing is handled through the use of domain names.
For example, to resolve the domain name bob@cisco.com, the source endpoint’s gatekeeper finds
the gatekeeper for cisco.com and sends the location request for target address bob@cisco.com to that
gatekeeper. The destination gatekeeper looks in its registration database, sees bob registered, and
returns the appropriate IP address to get to bob.
For example, to resolve the domain name bob@cisco.com, the source endpoint’s gatekeeper finds
the gatekeeper for cisco.com and sends the location request for target address bob@cisco.com to that
gatekeeper. The destination gatekeeper looks in its registration database, sees bob registered, and
returns the appropriate IP address to get to bob.
Note
Although H.225 does not require the use of a domain name with H.323 IDs, the
Cisco IOS Gatekeeper does require a domain name.
Cisco IOS Gatekeeper does require a domain name.
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When using E.164 addresses, call routing is handled through means of zone prefixes and gateway
type prefixes, also referred to as technology prefixes. The zone prefixes, which are typically area
codes, serve the same purpose as domain names in H.323-ID address routing. Unlike domain names,
however, more than one zone prefix can be assigned to one gatekeeper, but the same prefix cannot
be shared by more than one gatekeeper. With Cisco IOS Release 12.0(3)T and later, you can
configure inter-zone routing using E.164 addresses.
type prefixes, also referred to as technology prefixes. The zone prefixes, which are typically area
codes, serve the same purpose as domain names in H.323-ID address routing. Unlike domain names,
however, more than one zone prefix can be assigned to one gatekeeper, but the same prefix cannot
be shared by more than one gatekeeper. With Cisco IOS Release 12.0(3)T and later, you can
configure inter-zone routing using E.164 addresses.
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When using e-mail IDs, inter-zone routing is handled through the use of domain names—just as it
is with H.323 IDs. Again, the source endpoint’s gatekeeper finds the gatekeeper for the specified
domain and sends the location request for the target address to that gatekeeper.
is with H.323 IDs. Again, the source endpoint’s gatekeeper finds the gatekeeper for the specified
domain and sends the location request for the target address to that gatekeeper.