RTP TTL

The Oracle® Enterprise Session Border Controller (E-SBC) allows you to set, on a per media-policy basis, the number of hops RTP packets can traverse before they should be dropped.

This feature uses the standard IPv4 TTL and IPv6 Hop Limit field, comprised of 8 bits in the IP header to specify time to live. The E-SBC supports this feature over UDP transport. The E-SBC sets or replaces any existing value in the TTL and Hop Limit fields with your setting before sending packets out the egress interface. The E-SBC knows if it has already processed any given packet. It therefore, knows to set this value only the first time it processes a packet. In addition, the E-SBC never decrements this value and, therefore, never discards these packets itself.

To configure, you set rtp-ttl in the desired media-policy. You also apply the media-policy to the desired realm(s). The RTP TTL value range is from 0 to 255. By default, the feature is set to zero (Disabled).

ORACLE# configuration terminal
ORACLE(configure)# media-manager
ORACLE(media-manager)# media-policy
ORACLE(media-policy)# rtp-ttl 30

Display TTL statistics using the show datapath command. This command's syntax is platform dependent:

• Virtual Machine, Acme Packet 1100 and Acme Packet 3900 platforms

  Use show datapath usdp ppms tos

• Acme Packet 4600, Acme Packet 6100, Acme Packet 6300 and Acme Packet 6350 platforms

  Use show datapath etc-stats ppm tos <slot> <port>

This feature does not work on transcoded packets. After transcoding on Acme Packet platforms, the E-SBC sets the TTL value in all transcoded packets to 127.

The feature is RTC and is supported for HA deployments.