With this second AVB FAQ post, we conclude our 5-part AVB Demystified series of blog posts. To access all this information about AVB in once place, download our AVB Resource Guide. As AVB takes a greater hold in the professional installed audio industry, there will continue to be more questions about it. Let us know if there’s anything else you’d like answers to that we haven’t covered. You can also find answers on Cornerstone. AVnu Alliance is also a great resource for information on AVB. Without further ado, here’s 12 more questions and answers about AVB.
1) Is AVB a routable protocol?
AVB is currently supported at Layer 2 and is not routable at the moment.
2) Can I send AVB over a wireless link?
Class B traffic (which is not supported by Tesira) would be used here.
3) Can you mix AVB and non-AVB switches in the same network?
Yes. Non-AVB switches will act as a boundary to the AVB traffic.
4) Can CobraNet be in the same network as AVB?
It’s certainly possible to mix CobraNet and non-CobraNet traffic on the same network with no perceived problems. However, this is highly topology and usage dependent. There’s no guarantee that artifacts wouldn’t occur in different use cases. The CobraNet conductor assumes control and provides scheduling for all traffic on the network. When other traffic is present, it may delay delivery of CobraNet audio packets to the extent that the isochronous (beat) interval is exceeded. In this case, audio artifacts would likely be heard. For this reason we strongly discourage our customers from doing so. Segregating AVB traffic to VLAN 2 and placing CobraNet traffic on a separate VLAN or bridge/switch is recommended.
5) Can I make my existing infrastructure AVB-compliant?
AVB is enabled on existing infrastructure with the addition of AVB bridges/switches and endpoints.
6) When is there going to be a video device that uses AVB?
AVB data is purely that and is technically video-ready now. There is a requirement for hardware-based video endpoints. Manufacturers are still developing hardware to bring to market.
7) How do I set up VLANs with AVB?
AVB traffic is sent between an AVB device using tagged packets on VLAN 2. If a bridge/switch is not configured with VLAN 2, the AVB endpoints can create VLAN 2 using pVID.
8) What form does AVB traffic take on my system?
AVB traffic between the talker and listener is tagged traffic with a VLAN ID number of 2.
9) What cable do I need for AVB?
AVB switches work at Gigabit speeds or better. Cat-5e or better cable is required.
10) How do I know if AVB is working properly in my system?
This can be done via the switch console by monitoring the Multiple Stream Reservation Protocol. Tesira devices also have alarm indicators viewable in software, and the front panel of the device shows alarms due to AVB streams not operating as expected.
11) Is AVB traffic unicast or multicast?
AVB data traffic is 100% Layer 2 multicast. The standard allows for the use of unicast, but only if locally administered MAC addresses are used.
12) Is AVB CPU-intensive for the AVB bridge/switch?
Yes, AVB control traffic is CPU-intensive. The key factors relate to the numbers of ports and how many MSRP streams they will be using.
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