Remote Sip Phones; Benefits; Requirements; Interactions - Toshiba IP EDGE Description

Networking

Remote SIP Phones

Remote SIP Phones

Benefits

SIP end points provide the ability to use application specific devices such as door phones, wireless
devices, paging systems, etc.

Requirements

In order to connect a remote SIP end point to an IPedge node, any of the following mechanisms
can be used:
• SIP ALG (Application Layer Gateway)
• A SIP ALG device needs to be configured at both the main office and at the remote location
to transform the SIP/SDP session header addressing information.
• Firewall and NAT configurations to allow and forward SIP – UDP port 5060 to the IPedge
system.
• Media Relay Server (MRS) – If a SIP ALG does not operate as desired, the MRS function
within IPedge can be used to get a remote SIP end point registered with an IPedge node. To use
this method, within the Firewall and the NAT router at the main office, the following ports need
to be opened and forwarded; in order for the remote SIP end point to communicate to the
IPedge system:
• SIP – UDP port (5060)
• Media Relay Server – UDP port range (21000 - 22999)
• IPSec VPN – A remote SIP end point can also connect to an IPedge node over an IPSec VPN
connection.

Interactions

When connecting SIP devices across routers, some home routers implement SIP application layer
gateways. To work successfully, these gateways need to be configured to enable SIP
transformation. However, not all application layer gateways work consistently and if a given
gateway does not work, it should be disabled and the IPedge Static MRS function can be invoked
to still support these end points.
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IPedge General Description 04/13