RTP TTL

The Oracle® Enterprise Session Border Controller (ESBC) 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 ESBC supports this feature over UDP transport. The ESBC sets or replaces any existing value in the TTL and Hop Limit fields with your setting before sending packets out the egress interface. The ESBC 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 ESBC 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 ESBC sets the TTL value in all transcoded packets to 127.

The feature is RTC and is supported for HA deployments.