No-Op Packets

The device can send No-Op packets to verify Real-Time Transport Protocol (RTP) and T.38 connectivity, and to keep NAT bindings and Firewall pinholes open. The No-Op packets can be sent in RTP and T.38 formats:

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RTP No-Op: The RTP No-Op support complies with IETF Internet-Draft draft-wing-avt-rtp-noop-03 ("A No-Op Payload Format for RTP"). The IETF document defines a No-Op payload format for RTP. The draft defines the RTP payload type as dynamic. You can configure the payload type as described in the following procedure (default is 120).

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T.38 No-Op: T.38 No-Op packets are sent only while a T.38 session is activated. Sent packets are a duplication of the previously sent frame (including duplication of the sequence number).

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To configure the No-Op packet feature:

1.

Enable the feature, using the [NoOpEnable] parameter. You can also enable this feature per IP Profile (for SBC calls only), using the 'Generate No-Op Packets' parameter (see Configuring IP Profiles).

2.

Configure the interval between each No-Op packet sent by the device during the silence period (i.e., no RTP or T.38 traffic), using the [NoOpInterval] parameter.

3.

For RTP No-Op packets, configure the payload type of the No-Op packets, using the [RTPNoOpPayloadType] parameter.