The Block Direction feature provides the ability to restrict the SBC Core from sending a SIP request (outside an existing dialog) from its own network to the opposite network, but does not restrict receiving a SIP request (outside an existing dialog) from the opposite network to its own network.
Additionally, the Block Direction feature can restrict the SBC from sending a SIP request or receiving a SIP request, or sending and receiving a SIP request from its own network to the opposite network.
When implementing a function that sends a test call, the network can send a test call to the opposite network even if blocking is enabled. The SBC allows all test calls even if blocking is enabled on trunk groups.
% set addressContext <address context name> zone <zone name> sipTrunkGroup <SIPTG name> blockDirection <bothways | incoming | none | outgoing>