Cisco Cisco TelePresence Video Communication Server Expressway 관리 매뉴얼
Field
Description
Usage tips
Time to live
The interval (in seconds) at
which an H.323 endpoint
must re-register with the VCS
in order to confirm that it is
still functioning. Default is
1800.
which an H.323 endpoint
must re-register with the VCS
in order to confirm that it is
still functioning. Default is
1800.
Some older endpoints do not support the ability to periodically re-
register with the system. In this case, and in any other situation
where the system has not had a confirmation from the endpoint
within the specified period, it will send an IRQ to the endpoint to
verify that it is still functioning.
register with the system. In this case, and in any other situation
where the system has not had a confirmation from the endpoint
within the specified period, it will send an IRQ to the endpoint to
verify that it is still functioning.
Note:
By reducing the registration time to live too much, you risk
flooding the VCS with registration requests, which will severely
impact performance. This impact is proportional to the number of
endpoints, so you should balance the need for occasional quick
failover against the need for continuous good performance.
impact performance. This impact is proportional to the number of
endpoints, so you should balance the need for occasional quick
failover against the need for continuous good performance.
Call time to
live
live
The interval (in seconds) at
which the VCS polls the
endpoints in a call to verify
that they are still in the call.
Default is 120.
which the VCS polls the
endpoints in a call to verify
that they are still in the call.
Default is 120.
If the endpoint does not respond, the call will be disconnected.
The system polls endpoints in a call regardless of whether the call
type is traversal or non-traversal.
type is traversal or non-traversal.
Auto
discover
discover
by endpoints. The default is
On.
On.
To prevent H.323 endpoints being able to register automatically with
the VCS, set Auto discover to Off. This means that endpoints can
the VCS, set Auto discover to Off. This means that endpoints can
only register with the VCS if their Gatekeeper Discovery setting is
Manual and they have been configured with the VCS’s IP address.
Manual and they have been configured with the VCS’s IP address.
Caller ID
Specifies whether the prefix
of the ISDN gateway is
inserted into the caller's
E.164 number presented on
the destination endpoint.
of the ISDN gateway is
inserted into the caller's
E.164 number presented on
the destination endpoint.
Including the prefix allows the recipient to directly return the call.
About SIP
The VCS supports the SIP protocol. It can act as a SIP registrar, SIP proxy and as a SIP Presence Server.
The VCS can provide interworking between SIP and H.323, translating between the two protocols to enable
endpoints that only support one of these protocols to call each other.
endpoints that only support one of these protocols to call each other.
To support SIP:
■
must be enabled.
■
At least one of the SIP transport protocols (UDP, TCP or TLS) must be active. Note that the use of UDP is not
recommended for video as SIP message sizes are frequently larger than a single UDP packet.
recommended for video as SIP message sizes are frequently larger than a single UDP packet.
VCS as a SIP Registrar
For a SIP endpoint to be contactable via its alias, it must register its Address of Record (AOR) and its location with a
SIP registrar. The SIP registrar maintains a record of the endpoint’s details against the endpoint’s AOR. The AOR is
the alias through which the endpoint can be contacted; it is a SIP URI and always takes the form
SIP registrar. The SIP registrar maintains a record of the endpoint’s details against the endpoint’s AOR. The AOR is
the alias through which the endpoint can be contacted; it is a SIP URI and always takes the form
username@domain
.
When a call is received for that AOR, the SIP registrar refers to the record to find its corresponding endpoint. (Note
that the same AOR can be used by more than one SIP endpoint at the same time, although to ensure that all
endpoints are found they must all register with the same VCS or VCS cluster.)
that the same AOR can be used by more than one SIP endpoint at the same time, although to ensure that all
endpoints are found they must all register with the same VCS or VCS cluster.)
A SIP registrar only accepts registrations for domains for which it is authoritative. The VCS can act as a SIP registrar
for up to 200 domains. To make the VCS act as a SIP registrar, you must configure it with the
for up to 200 domains. To make the VCS act as a SIP registrar, you must configure it with the
for which it
will be authoritative . It will then handle registration requests for any endpoints attempting to register against that
domain. Note that the VCS will also accept registration requests where the domain portion of the AOR is either the
domain. Note that the VCS will also accept registration requests where the domain portion of the AOR is either the
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Cisco TelePresence Video Communication Server Administrator Guide
Protocols