Media Clock Offset (AES67)

EHX v. 13.0 and above.

In a situation where AoIP (AES67) traffic is required to traverse VLANs, LANs and other broadcast segments, it may be necessary to use media clock offset in order to introduce some PTP clocking tolerance into the network. For a Clear-Com AoIP system the overall network delay must not exceed 2 ms when using 125 µs packet size, or 20 ms when using 1 ms packet size. If the network delay is longer than the stated times, the packet is thrown away, resulting in a loss of sync and audio . Media clock offset values enable the system administrator to allow for longer delays in the network.

When the system detects a network delay above (or below) the Clear-Com parameters, a message will be printed in the EHX event log. If the delay details are available to the system, those will be included in the message.

Note: The reported delay figure is based on the current media clock offset value (default =0).

Media clock offset can be set in a number of contexts:

ClosedFor a panel

ClosedFor 3rd party AoIP streams received into the EHX system

ClosedFor an IP transceiver

The unit for media clock offset is microseconds. You can configure any number between ±2’147’483’647 microseconds. This gives you the ability to adjust the media clock offset by ±2000 seconds.