Snom ONE IP, Техническое руководство

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Deploying the snom ONE IP Telephone System
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30.
Rewrite global numbers:
When you are using a trunk, you may have to rep-
resent the telephone number in a specific format. For example, in the NANPA
area, you might want to use 10 or 11 digits to represent a national number.
If you are using several trunks, you can represent the same number in different
styles depending on the trunk. The Rewrite global numbers setting corre-
sponds to the
Country Code
setting (see page 94):
31. Failover Behavior: When the trunk receives an error code, it might send the
call back to the dial plan and continue the matching process. The system con-
tinues the dial plan with the next highest priority, ignoring entries with lower or
same priority. This is useful when the trunk is just a “trial” to place the call. One
example is when several PSTN gateways are available for terminating the call
and one gateway does not accept any more calls. Another example is when you
first try to route the call via a peer-to-peer call using ENUM or other location
methods and only if such resolution does not result in a connection fallback to
a PSTN call. The setting allows four behaviors:
—
No failover: This is the default behavior. In this case, the caller will
receive the error code as a result of the attempted call.
—
On 5xx and 408 error codes: This will trigger failover only when a 5xx
or 408 class error code is received. PSTN gateways typically return 5xx
class error codes when all channels are in use; however, this mode will
allow you to switch to the next PSTN gateway when a line is busy and
will not trigger the failover.
—
On all error codes: In this case, all error codes will trigger the failover
process. Note that call redirect will also be treated as an error code, as