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max_forwards

Created by Ryan Harris, last modified on 2018.02.08

max_forwards​

integer Contains the current Max-Forwards value provided in the originating request. The Max-Forwards value is decremented by one for each hop in a SIP call, when the Max-Forwards value is depleted the receiving agent must not pass the call onwards.

The max_forwards variable may be set on an outbound channel, some providers such as BT IP Exchange insist on a minimum value to faithfully terminate the call, 50 in BT's case.

(warning) If the max_forwards value is reset it can cause potential cyclic calls between two operators who loop calls back to each other in error. Use wisely.

Usage

Bridge an incoming call to a provider requiring a minimum Max-Forwards value:

<action application="bridge" data="{max_forwards=65}sofia/gateway/ipexchange/442920180123"/>