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H323 Telephone Installation
Page 56
Issue 23e (Friday, February 15, 2019)
IP Office™ Platform 11.0
Comments on this document? [email protected]
2.12 Other Installation Options
2.12.1 Remote H.323 Extensions
For IP Office Release 8.0+, the configuration of remote H.323 extensions is supported without needing those extensions
to be running special VPN firmware. This option is intended for use in the following scenario:
·
The customer LAN has a public IP address which is forwarded to the IP Office system. That address is used as the
call server address by the H.323 remote extensions.
·
The user has a H.323 phone behind a domestic router. It is assumed that the domestic router allows all outbound
traffic from the home network to pass through and allows all symmetric traffic. That is, if the phone sends
RTP/RTCP to a public IP address and port, it will be able to receive RTP/RTCP from that same IP address and port.
Configurations otherwise are not covered by this documentation.
·
The system can be configured to support remote H.323 extensions in the case where NAT is used in the
connection path. This could be the case where the IP Office is located behind a corporate NAT/Firewall router
and/or the H.323 phone is located behind residential NAT enable router. The use of this option and the
interaction and configuration of external third party elements is beyond the scope this help file.
·
When the public IP address of the corporate router is unknown, you need to configure a STUN server in the the
IP Office LAN's
Network Topology
settings. Note however that this option is not supported if the
Firewall/NAT Type
is set to
Symmetric Firewall
or
Open Internet
.
·
Enabling the
Allow Remote Extn
option also makes visible the configuration of the
RTP Port number Range
(NAT)
settings.
·
Supported Telephones
Currently, remote H.323 extension operation is only supported with 9600 Series phones already supported by the
IP Office system.
·
License Requirements
By default, only 4 users can be configured for remote H.323 extension usage without needing licenses. Additional
users can be configured if those additional users are licensed and configured with either
Teleworker
or
Power
User
user profiles.
Customer Network Configuration
The corporate LAN hosting the IP Office system requires a public IP address that is routed to the LAN interface of the IP
Office system configured for remote H.323 extension support.
STUN from the IP Office system to the Internet is used to determine the type of NAT being applied to traffic between the
system and the Internet. Any routers and other firewall devices between the H.323 phone location and the IP Office
system must allow the following traffic.
Protocol
Port
Description
ICMP
–
Incoming ICMP to the IP Office system's public IP address must be allowed.
UDP
1719
UDP port 1719 traffic to the IP Office system must be allowed. This is used for H225 RAS
processes such as gatekeeper discovery, registration, keepalive, etc. If this port is not open
the phone will not be able to register with the IP Office system.
TCP
1720
TCP port 1720 traffic must be allowed. This is used for H.225 (call signalling). The address
used can be adjusted using the
Remote Call Signaling Port
setting.
RTP
Various
The ports in the range specified by the system's
RTP Port Number Range (NAT)
settings
must be allowed.
RTCP
UDP
5005
If the system setting
Enable RTCP Monitoring on Port 5005
has been enabled, traffic on
this port must be allowed to include remote H.323 extensions in the monitoring.