Configuring The Routing Tables - 3Com VCX V7122 User Manual

Configuring the Routing Tables

Use this submenu to configure the gateway's IP Tel and Tel IP routing tables and their
associated parameters.
Tel to IP Routing Table
The Tel to IP Routing Table is used to route incoming Tel calls to IP addresses. This routing
table associates a called / calling telephone number's prefixes with a destination IP address
or with an FQDN (Fully Qualified Domain Name). When a call is routed through the VoIP
gateway (Proxy isn't used), the called and calling numbers are compared to the list of
prefixes on the IP Routing Table (up to 50 prefixes can be configured); Calls that match
these prefixes are sent to the corresponding IP address. If the number dialed does not match
these prefixes, the call is not made.
When using a Proxy server, you do not need to configure the Telephone to IP Routing Table.
However, if you want to use fallback routing when communication with Proxy is lost, or to use
the 'Filter Calls to IP' and IP Security features, or to obtain different SIP URI host names (per
called number), you need to configure the IP Routing Table.
Possible uses for Telephone to IP Routing can be as follows:
Can fallback to internal routing table if there is no communication with the Proxy.
Call Restriction – (when Proxy isn't used), reject all outgoing Tel IP calls that are
associated with the destination IP address: 0.0.0.0.
IP Security – When the IP Security feature is enabled (SecureCallFromIP = 1), the VoIP
gateway accepts only those IP Tel calls with a source IP address identical to one of the
IP addresses entered in the Telephone to IP Routing Table.
Filter Calls to IP – When a Proxy is used, the gateway checks the Tel IP routing table
before a telephone number is routed to the Proxy. If the number is not allowed (number
isn't listed or a Call Restriction routing rule was applied), the call is released.
Always Use Routing Table – When this feature is enabled (AlwaysUseRouteTable = 1),
even if a Proxy server is used, the SIP URI host name in the sent INVITE message is
obtained from this table. Using this feature users are able to assign a different SIP URI
host name for different called and/or calling numbers.
Assign Profiles to destination address (also when a Proxy is used).
Alternative Routing – (When Proxy isn't used) an alternative IP destination for telephone
number prefixes is available. To associate an alternative IP address to called telephone
number prefix, assign it with an additional entry (with a different IP address), or use an
FQDN that resolves to two IP addresses. Call is sent to the alternative destination when
one of the following occurs:
No ping to the initial destination is available, or when poor Quality of Service (QoS)
(delay or packet loss, calculated according to previous calls) is detected, or when a
DNS host name is not resolved. For detailed information on Alternative Routing, see
Configuring the Gateway's Alternative Routing (based on Connectivity and QoS)
page 150.
When a release reason that is defined in the 'Reasons for Alternative Tel to IP
Routing' table is received. For detailed information on the 'Reasons for Alternative
Routing Tables' see
52
Reasons for Alternative Routing
3Com VCX V7122 SIP VoIP Gateway User Manual
on page 57.
on