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AVB over Fiber

Hello. I have 2 x Summit X440-24P switches with a 10053-PRO installed in each and connected to fiber. One switch has 3 x AVB devices connected. The other switch had 1 x AVB device connected. Both devices have AVB enabled on all ports. I can ping devices on either switch from the other switch. I have passed data traffic down the default VLAN. I can see all devices joining the AVB VLAN on their respective switches. But the AVB VLAN does not appear to be propagating across the fiber. I have no AVB audio propogating between devices on the fiber. I reached out to Biamp (whose audio processors we are using) and they suggested a couple of things, none which appear to solve the problem as I still have to AVB audio propagating between devices. Any help you can give to an old AV guy is definitely appreciated! Question......when looking at the devices on the AVB VLAN in my configuration, will the number of devices on the VLAN show as 4 on both ends once configured properly? Currently I have 3 on the one and 1 on the other. I want understand this better for future reference and trouble shooting. Thanks for the help.

5 replies

Userlevel 4

Is the AVB VLAN spanned across the fiber. The uplink fiber port should also be included the AVB VLAN in order to pass that VLAN across the link. Is this the case?

For example: SW1 has AVB & Default VLANs and SW2 has AVB & Default VLANs.

SW1 port <#> ----Fiber---- <#> port SW2

The fiber port would need to be in the AVB VLAN in order to pass traffic across it on that VLAN.
Userlevel 6

What software version is running on the switches (show version)? I believe there are a few known AVB issues that specifically impact fiber ports. I would suggest upgrading to the latest software (currently EXOS as it contains all available bug fixes and enhancements.

What is the port status and propagation delay of the fiber ports (show network-clock gptp port )? The port status should be "master" or "slave" and the propagation delay should be lower than the propagation delay threshold. If not, that could indicate a gPTP problem on the port (a common reason for AVB problems.)

Also, and based on your description I believe this has already been done, make sure you enable AVB globally and at the port level (enable avb, enable avb port )

To your question on vlan membership, yes all AVB endpoint ports should join the AVB VLAN (assuming they are all participating in a stream of course.) So, all AVB switch connections and endpoint connections should be present in the AVB VLAN. Some of the Bi-Amp equipment has a non-AVB MGMT port. These ports will not participate in AVB and you will not see them in the AVB VLAN nor will they be AVB capable ports.
Thanks for the replies. The AVB VLAN is dynamically created. So it cannot be added to the fiber port. I have tried and the switch tells me that you cannot do this with a dynamically created VLAN. Based on what I have experienced thus far, I would imagine that the AVB VLAN has to "see" the AVB timing signals through the fiber port and then will automatically add the VLAN to the port. I'm running 15.7.2 per my last email with Biamp. Also, Biamp had me adjust the pdelay threshold to 5000 nanoseconds. I will get the latest version of software installed and see what that does for me. I will also check for master/slave port status on the fiber ports. Thanks again for the help.
Okay. I'm stupid. Apparantly AVB wasn't enabled on all ports on the switch for the old system. I could have sworn that I checked that. Is there any real reason to not enable AVB on all ports? Thanks again for all the help.
Userlevel 7

"I have tried and the switch tells me that you cannot do this with a dynamically created VLAN"

you need to convert the VLAN to static in order to be able to add ports to it. You can do so by renaming the VLAN.

"Is there any real reason to not enable AVB on all ports? "

Enabling AVB on every port is by far the simplest thing. The main drawback I can imagine is a security issue. Depending on your usage and environment, this is important or not. With dynamic VLAN creation and adoption without control, one can connect a device and have access to the network. You can control that by enabling AVB only on specific ports, and/or restrict the VLAN allowed on some ports.