During a STUN connectivity check phase, the SBC prioritizes the processing of STUN packets that match the source addresses received in the candidate lines of the ICE SDP received from the peer. The Source Address Filtering mechanism for ICE is enabled by default. The filtering mechanism is applicable to the following address types:
When the ICE Source Address Filtering is enabled, STUN packets that are received during the connectivity check phase and do not match the addresses sent by the peer are still processed but at a reduced rate. This allows Peer Reflexive Candidates to still be learned through STUN.
This has no impact during the stable call when only packets received from the learned source address are processed and rest are dropped by default.
On SBC main screen, go to All > Address Context > Zone > Sip Trunk Group > Services > Nat Traversal > Ice Source Address Filter Priority.
The Ice Source Address Filter Priority can be checked for each Address Context, for each Zone, for each Sip Trunk Group created or for all the Address Contexts, Zones and Sip Trunk Groups created. Use the drop-down box to select the desired Address Context, Zone and Sip Trunk Group.
The Edit Ice Source Address Filter Priority window is displayed.
The following parameters are displayed: