Cisco Cisco TelePresence Video Communication Server Expressway 관리 매뉴얼

다운로드
페이지 295
53
D14049.08 
November 2010
Grey Headline (continued)
CISCO TELEPRESENCE
 VIDEO COMMUNICATION SERVER
ADMINISTRATOR GUIDE
Registration control
Endpoint registration
For an endpoint to use the VCS as its H.323 gatekeeper or SIP 
registrar, the endpoint must first register with the VCS. The 
VCS can be configured to control which devices are allowed to 
register with it. Two separate mechanisms are provided:
• 
 based on the username and 
password supplied by the endpoint
• 
a simple Registration Restriction Policy that uses 
 to specify which aliases can and cannot register 
with the VCS, and the ability to control registrations based on 
IP addresses and subnet ranges through the specification of 
subzone membership rules and 
.
It is possible to use both mechanisms together. For example, 
you can use authentication to verify an endpoint’s identity from a 
corporate directory, and registration restriction to control which 
of those authenticated endpoints may register with a particular 
VCS. 
This section gives an overview of how endpoints and other 
devices register with the VCS, and then describes the two 
mechanisms by which registrations can be restricted.
For specific information about how registrations are 
managed across peers in a cluster, see th
 section.
Registration overview
MCU, gateway and Content Server registration
H.323 systems such as gateways, MCUs and Content Servers 
can also register with a VCS. They are known as locally 
registered services. These systems are configured with their own 
prefix, which they provide to the VCS when registering. The VCS 
will then know to route all calls that begin with that prefix to the 
gateway, MCU or Content Server as appropriate. These prefixes 
can also be used to control registrations.
SIP devices cannot register prefixes. If your dial plan dictates 
that a SIP device should be reached via a particular prefix, 
then you should add the device as a neighbor zone with an 
associated search rule using a pattern match equal to the prefix 
to be used.
The Cisco TelePresence MPS 200 and MPS 800, and the 
Cisco TelePresence Content Server both support 
Expressway. They can therefore register directly with a 
VCS Expressway for firewall traversal.
Registrations on a Cisco VCS Expressway
If a traversal-enabled endpoint registers directly with a VCS 
Expressway, the VCS Expressway will provide the same services 
to that endpoint as a VCS Control, with the addition of firewall 
traversal. Traversal-enabled endpoints include all Cisco 
TelePresence Expressway™ endpoints and third party endpoints 
which support the ITU H.460.18 and H.460.19 standards. 
Endpoints that are not traversal-enabled can still register with 
a VCS Expressway, but they may not be able to make or receive 
calls through the firewall successfully. This will depend on a 
number of factors:
• 
whether the endpoint is using SIP or H.323
• 
the endpoint’s position in relation to the firewall
• 
whether there is a NAT in use
• 
whether the endpoint is using a public IP address
For example, if an endpoint is behind a NAT or firewall, it may not 
be able to receive incoming calls and may not be able to receive 
media for calls it has initiated. SIP endpoints can also work 
behind a NAT but can only receive video if they send it as well.
To ensure firewall traversal will work successfully for H.323 
endpoints behind a NAT, the endpoint must be traversal-enabled.