Tandberg MCU transcoding

[Timur]

Does anyone know about Tandberg’s MCU transcoding capability?
I observed real situation: I had one old H.261 VCON terminal and 3 T770 and Tandberg MCU received from each T770 H.263 and sent them H.261.
That is Tandberg MCU do not know what is trascoding.
Does anyone explain this?
P.S. Software version of Tandberg MCU was d36. :tired:

[trapehzoid]

the tandberg mcu can take mix different protocals incoming and outgoing. So having H.263 in and H.261 out is not to be unexpected.

or is it you are concerned why they got H.261 at all?

[Timur]

Ok. I have the following scheme:
1. Tandberg MCU as MP and MC
2. Old PCI card based on PC from VCON
3. Several number of Tandberg terminals

Tandberg MCU receives from VCON and sends to VCON H.261 coding video.
Tandberg MCU receives from Tandberg terminals H.263 and sends to these terminals H.261 video.

Such behavior is bug and it appears when Tandberg MCU operates with old equipment based on H.323 v1.

[trapehzoid]

Ok. I have the following scheme:
1. Tandberg MCU as MP and MC
2. Old PCI card based on PC from VCON
3. Several number of Tandberg terminals

Tandberg MCU receives from VCON and sends to VCON H.261 coding video.
Tandberg MCU receives from Tandberg terminals H.263 and sends to these terminals H.261 video.

Such behavior is bug and it appears when Tandberg MCU operates with old equipment based on H.323 v1.

Try connecting the sites at different speeds from each other

[Timur]

There is no difference. Probably Radvision have done deep error in H.323 toolkit.

[trapehzoid]

There is no difference. Probably Radvision have done deep error in H.323 toolkit.

You sure seem to make pretty big assumptions with zero basis.

Have you even tried calling for support on the MCU? Have you looked at the h323 traces?

[Timur]

I prefer ethereal and SPAN on Catalyst.

[trapehzoid]

I prefer ethereal and SPAN on Catalyst.

Ok, but can you read what you are seeing?

I don't put much faith in that ability of yours.

Why bother going through the trouble of using a packet sniffer and altering your switch configuration just to take a trace of something the device itself gives you?

So you can be 'cool' and use a packet sniffer?

I prefer the simple effective ways.. leave the nerd flexing at home.

[Timur]

I offer you to study CCNA course from Cisco and probably you will understand what is sniffer and what to do with it.

[trapehzoid]

I offer you to study CCNA course from Cisco and probably you will understand what is sniffer and what to do with it.

I'm CCNP thank you very much..

oh.. and ANS.1 decoding and understanding H.225 and H.245 aren't covered in either CCNA or CCNP.. so try again.

Try picking up a book on H.323 (even VoIP) and start understanding the basics of negotiation and capabilities for H.323..

Then go back and talk to your support guy who will tell you how to make the MCU transcode.. like I did half a page up.

[Timur]

In spite of your deep study in CCNP and H.323 I think you should first of all realize what trascoding is and then write so threatening words …
Good luck.

[11B-33T]

http://www.smprime.com.ph/uploads/images/SecImg1_narrative-cinema.jpg

:surprised breaking out the popcorn & kicking back to watch the show!

[trapehzoid]

In spite of your deep study in CCNP and H.323 I think you should first of all realize what trascoding is and then write so threatening words …
Good luck.

Really? who's the one who can't get their MCU to work?

My TANDBERG 16+16 transcodes just fine.

If you could even fathom how to take the trace, I'd even decode it for you, but since you can't even make the vcon connect at a different speed from the other two endpoints.. I will not hold my breathe.

Why don't you go get your mother to read this thread for you so she can explain how to get your MCU to send two different video streams. I guess following directions wasn't on those certification tests you took.

[Trussy]

Hi Traphezoid! We encountered the same problem when our IT Network guru (an Engineer) and I tried to get a help desk kid to understand that he didn't really know what he was talking about! In the end all he could offer as assistance were insults to try to hide his ineptness! (he tried to tell our engineer that he had a switch setting incorrect despite being assured a few times that it had been checked)

[trapehzoid]

Hi Traphezoid! We encountered the same problem when our IT Network guru (an Engineer) and I tried to get a help desk kid to understand that he didn't really know what he was talking about! In the end all he could offer as assistance were insults to try to hide his ineptness! (he tried to tell our engineer that he had a switch setting incorrect despite being assured a few times that it had been checked)

Sorry to hear that.. still doesn't help Timur read how to make his MCU transcode. The MCU will not send out different video protocals to sites connected at the same speed. Maybe after reading it for the fourth time he'll figure that out.

The MCU will take any combination of inputs, but will send the same picture out to all sites connected at the same speed.

As for the network setting.. you'd be amazed how many people do not understand the simple concepts about ethernet duplex. Not only setting it correct (come on.. leave it at auto and leave it alone unless it can't negotiate), but people can't understand why half duplex is bad for video.

[Sean Lessman]

...the end all he could offer as assistance were insults to try to hide his ineptness! (he tried to tell our engineer that he had a switch setting incorrect despite being assured a few times that it had been checked)

Having been on the manufacturing side of the fence for over 10 years, I will say that 90%+ cases where the person on the other end of the phone 'assured' me it had been checked -- it hadn't. Remember, the help desk people are here to help you and sometimes they might find something you overlooked or assumed was working.

Duplex issues are very common most people do not really understand why they are problems.

Sean

[trapehzoid]

Having been on the manufacturing side of the fence for over 10 years, I will say that 90%+ cases where the person on the other end of the phone 'assured' me it had been checked -- it hadn't. Remember, the help desk people are here to help you and sometimes they might find something you overlooked or assumed was working.

Duplex issues are very common most people do not really understand why they are problems.

Sean


Sean, since you are TANDBERG, what is your take on Timur's problem with his MCU?

[Sean Lessman]

Sean, since you are TANDBERG, what is your take on Timur's problem with his MCU?

Trap,

You were correct in suggesting he try different speeds. Today the TANDBERG MCU transcodes any audio and will take in any video. It will product 2 outgoing video streams if the rates are different. If the rates are not different, the MCU will not go into transcoding mode.

Sean

[Timur]

Sean,
Am I right that Tandberg's 16+16 module can support only two simultaneously transcoding by speed streams? Could you make clear situation?

[Sean Lessman]

Sean,
Am I right that Tandberg's 16+16 module can support only two simultaneously transcoding by speed streams? Could you make clear situation?

The TANDBERG MCU today supports 2 different outgoing video stream rates. It allows any incoming audio, video and speed. The endpoints will not have their rates changed.

Sean

[Timur]

Dear Sean,

Excuse me your explanation is not so clear. Trascoding is ability to process multimedia stream with param: audio codec, video codec, speed, fps, resolution. The real trascoding is receiving streams with different params and sending streams with the same params. That is if I have 3 terminals with different speeds, different codecs, fps and resolutions with feature transcoding each terminal receives the streams with the same params.
As I can understand if I have 3 terminals (768, 512, 384 Kbps) with different speeds using Tandberg MCU transcoding server will send to terminals streams with 2 speeds (768&512, 768&384, 512&384 Kbps). And one terminal if it can not process asymmetrical stream will be down. And what is priority to make choice of speed value? Is it right explanation?

[Yukikaze]

Transcoding simply refers to the ability to translate between encodings to allow all participants to receive content. There is no good reason to always send back exactly the same standard, resolution and fps as a site is sending. Say nobody in your conference are dual stream enabled and one site is trying to send a pc presentation with high resolution for example, say 1024x768 H.263+. Do you really want this presentation transcoded to H.263 CIF just so the standards will look nice and symetric at the two other sites(which are sending normal video)? The quality would be awful and this is definitly not the behaviour most people would want of a transcoding MCU.

It is fair to complain about the Tandberg MCU's transcoding not being optimal in all cases because of the "two rates" restriction, but it does in fact always solve the problem of transcoding incoming streams to standards the other participants can receive. The Tandberg approach sort of assumes that most sites will be connecting at the same bandwidth and have roughly the same capabilities, but has a fallback for worse sites and will encode a version of the conference with the best commonly supported rate/standard among those "non-standard-rate" sites. In practice this means that the rate of the second outgoing stream is dictated by that of the lowest rate participant and similarly, the site with the worst video capabilities dictate the video standard.

Edit: No site will ever be down because there are minimum requirements for videoconferencing equipment. All devices must support H.261 for example. What will happen in the case where you have two low-rate sites not supporting asymetric standards connecting at different rates is that the higher rate site simply will receive the lower rate video, even though it is connected at a higher rate. This approach may waste bandwidth in some cases, but always works.

[Timur]

It is perfect to use chat to have knowledge about product capability but it seems like purchasing of black cat in bag. Ok, it will be great to see strict capability in datasheet.
Sean?

[Yukikaze]

All products have downsides/implementation issues that aren't documented(or plain undocumented bugs for that matter) so if you expect to be able to buy network infrastructure products after only comparing manufacturer's datasheets you will indeed be in for many surprises in the field, no matter what product you decide on. In the end people just have to test such complicated products in their production environment to figure out which product is best suited for them.

Anyway, if the rate issue is supremely important to you my advice is to look at other MCUs with better functionality in this area, Codian for example. The Tandberg MCU seems primarily targeted at organizations with a high level of standardization in their video communications. In such environments it's other features, especially its extreme ease of use and stability, make it one of the better choices though.

[Timur]

I work at system integration. I need to compare products from different vendors. My standard comparison table of large MCUs includes feature products from Polycom, Cisco or Radvision, HUAWEI and Tandberg (large Codian now is only phantom). Previously I knew (had data from vendor closed sites and conversation with vendor) for what segment of market every MCU can be implied and I could propose solution for ISP or large corporate. And I was under impression about Tandberg MPS because of simplicity to manage. And in spire of absence of internal billing capability MPS could be imply for large organizations. But after a year of close work with vendor I knew from chat that product has strong restriction. Based on this restriction MPS is in latest position of list products. It is very strange vendor behavior.

[William]

While its true that the Codian chassis is not yet shipping, they have committed to 100% trade in on the stackables towards a purchase of the chassis. The Codian MCU will do 40 streams and each one will be transcoded, meaning that every user can have a different speed and codec, which will vastly simplify the configuration.

[Sean Lessman]

While its true that the Codian chassis is not yet shipping, they have committed to 100% trade in on the stackables towards a purchase of the chassis. The Codian MCU will do 40 streams and each one will be transcoded, meaning that every user can have a different speed and codec, which will vastly simplify the configuration.

Will, as a Codian employee and co-founder of the company, don't you mean 'we have committed'?

Sean

[Yukikaze]

And I was under impression about Tandberg MPS because of simplicity to manage. And in spire of absence of internal billing capability MPS could be imply for large organizations. But after a year of close work with vendor I knew from chat that product has strong restriction. Based on this restriction MPS is in latest position of list products. It is very strange vendor behavior.

The way I look at it the Tandberg MCU is ideal for large organizations because such organizations usually have the ability to enforce standards on rates throughout the organization - effectively making the rate limitation a non-issue. I do see its limitations can be a problem for service providers who don't have any control over what rates people connect at though.

[Timur]

I completely agree that it is possible to say that this feature is feature by design (Cisco says this when they can’t do something). However MCU consist a few numbers of features it hasn’t software like Cisco IOS. And this is a few amount of features are used for huge marketing. They say that they are leader but at same time … Very strange, very …

[trapehzoid]

Troll .

[Yukikaze]

I'll just end my participation in this thread by saying that an MCU is much more than its transcoding ability. Transcoding is important, yes, but other things, such as supporting endpoint features or management features, may well be more important to a given customer. Due to this, going from the observation that the Tandberg MCU isn't the most flexible transcoding solution available to the conclusion that it is unsuitable for large organizations may actually cause you to end up with a non-optimal solution. It is a very solid product, worthy of consideration in a variety of situations. It is clearly not the best choice in all cases, but neither are any of the other contenders.

[trapehzoid]

I'll just end my participation in this thread by saying that an MCU is much more than its transcoding ability. Transcoding is important, yes, but other things, such as supporting endpoint features or management features, may well be more important to a given customer. Due to this, going from the observation that the Tandberg MCU isn't the most flexible transcoding solution available to the conclusion that it is unsuitable for large organizations may actually cause you to end up with a non-optimal solution. It is a very solid product, worthy of consideration in a variety of situations. It is clearly not the best choice in all cases, but neither are any of the other contenders.

Well put. :thumbup:

[Timur]

Completely agree with you. Yes entourage is useful especially for flower-shop.

[Skylark]

Well just to get back to the orginal question:

In my experience the old VCON doesnt know how to "autonegociate" properly.

This has nothing to do with Transcoding.

So If your gona make call with a old VCON endpoint make sure you have the connection fixed to H263 or H261

[Timur]

If you want I can send you log file from Tandberg MCU and you will see that Tandberg MCU receives both from old PCI card from VCON H.261 and Tandberg MXP endpoints H.263 and then MCU send H.261 both PCI card and Tandberg endpoints. They use one speed for connection restricted by order (customer is ministry).

[bdldunworthy]

LOL


Hey Trapehzoid... Do you know of any good books on H.323 and VOIP?


BDL