Tesira began shipping a year ago on May 14th. In that relatively short period of time, we’ve sold four-figures worth of AVB-enabled products. That’s a lot, considering many companies still have a “wait and see” attitude towards AVB. Check out our ever-growing list of Tesira-centric case studies if you’re still unsure about where AVB is headed.
During this past year, we’ve discovered that there’s a lot of information out there that doesn’t tell the whole story about what AVB is and isn’t. We’d like to correct some of those misconceptions to help you gain a better understanding of this emerging technology.
Myth #1: Since AVB is not a proprietary protocol, there’s no support.
Regardless of whether it’s proprietary or not, you’re always going to go back to the product manufacturer when you need support.
Take Wi-Fi, for instance. It’s not proprietary either, but if you have a problem with the wireless LAN adapter in your laptop, you contact the laptop manufacturer for support, not the Wi-Fi consortium. It’s the product manufacturer that’s responsible for support of all aspects of its product, not the creator of the technology it uses. The same holds true for AVB, and we back it up with a 5-year equipment warranty on all of our DSP products.
Myth #2: There’s no “V”.
It’s probably more accurate to say “there’s not as much ‘V’ available today on the market as people would like.” There were at least two vendors in the AVnu Pavilion at ISE 2013 showcasing video transmission using AVB, and switch manufacturers are having on-going discussions with video vendors regarding transmission over their AVB-enabled switches.
Video transmission standards are complicated, and it’s going to take manufacturers some time to get their products to market. Personally, I’d prefer vendors take the time to release a robust, stable product to market rather than rush something that’s not market-ready on day one.
Myth #3: Firmware upgrades for Layer 3 protocols are all you need for true AVB stream transmission.
Honestly, we don’t know. I suppose this one remains not debunked (“bunked”, still?).
However, you’ll still need to use AVB-enabled switches to transmit via AVB end-to-end and communicate with other AVB-enabled devices. The AVB standards require the use of AVB-enabled switches to automatically manage MSRP, QoS, and more.
Myth #4: There are no AVB-enabled switches available.
Not true. There are at least six AVB-enabled switches currently available (in alphabetical order):
1) Extreme Networks Summit® X440 series
2) Extreme Networks Summit X460 series
3) Extreme Networks Summit X670 series
4) Lab X Technologies Titanium 411 AVB Switch
5) NETGEAR GS724T 24 Port Ethernet AVB Switch
6) Pathport VIA 10+1 Port Ethernet AVB Switch
Myth #5: With 8 hops, AVB fails.
This assertion is incorrect. The latency of AVB provides 2ms transversal time over 7 hops in a 100Mbit Ethernet network, which is a requirement in certain transmissions, but that doesn’t mean it stops working in 8 hops. Here is a direct comment from the AVnu Alliance:
“There is no limitation number of switch hops in IEEE AVB standards. This may be a misunderstanding of rationale for the default 2ms presentation time, which is achievable at 7 hops of 100MB. This default can be used for even more hops at 1GB Ethernet, or the presentation time can be adjusted for more hops at 100MB.”
Myth #6: If up to 75% bandwidth can be reserved for AVB streams, there’s no bandwidth left for other data.
When the AVB-enabled source (“talker”) wants to transmit data, it tells the switch how large the stream is, and the switch determines whether or not that bandwidth is available. If so, it reserves space for that stream. If not, the stream does not get transmitted.
What’s important to understand about bandwidth reservation is that it’s on a port-by-port basis. If your switch has 24 ports, only 75% of one port is being reserved for AVB traffic. Depending on how your network is set-up, you can alleviate any potential bottlenecks by setting-up your VLANs in a robust fashion–putting high volume sources on different ports. Anecdotal, do-not-quote-us feedback points to around 8% typical reservation for audio (only) streams on a 1GB switch, whereas video streams may be around 3GB on a 10GB switch (30%).
Myth #7: AVB is not interoperable.
Also not true. The AVnu Alliance, of which Biamp and a number of other AV industry leaders are members, will “create compliance test procedures and processes that ensure AVB interoperability of networked A/V devices, helping to provide the highest quality streaming A/V experience.” In fact, Biamp has hosted interoperability workshops where other members bring in their equipment, interconnect it with each other, and test it to ensure it does, in fact, work properly. Numerous manufacturers will also be at InfoComm 2013 in the AVnu Pavilion to demonstrate product interoperability.
There’s also the AVnu Alliance certification program. This program provides compliance testing to ensure that AVB equipment complies with the IEEE 802.1 standards for AVB, including protocol quality, consistency, and interoperability with other AVB-enabled devices.
Tesira also supports communications via CobraNet® using our SCM-1 expansion cards. You can transmit AVB streams via a Tesira SERVER or SERVER-IO, while also transmitting BGM or other audio content over your existing CobraNet network.
Myth #8: Layer 3 protocols are better than Layer 2.
This is one we’ve heard a lot about, and the answer is nuanced enough that we’re going to dedicate an entire blog post to the subject in a couple of weeks. Conditionally, the answer is “no,” just as Layer 2 protocols are not inherently better than Layer 3. There are benefits and drawbacks to both. If one were definitively better than the other, the inadequate one would cease to exist.Hopefully that answers some of the questions you have regarding AVB. If you have additional questions, please contact us.