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Bandwidth shaping - Is iPlayer treated differently from other streaming media?

ModelCitizen
Grafter
Posts: 46
Registered: ‎30-04-2008

Bandwidth shaping - Is iPlayer treated differently from other streaming media?

I'm tring to problem solve my connection to iPlayer radio via my Squeezeboxes.
All streaming (Shoutcast, Napster, Last.fm) work fine but iPlayer often continuously rebuffers. It was a big problem this evening and early yesterday evening for instance.
It would help me work out what the problem is if PlusNet could categorically state that they bandwidth shape streamed services as a whole and do not treat iPlayer any differently from any other streamed services.
Thanks.
MC
24 REPLIES
Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

Just did a wireshark capture on BBYW Option 1 and it comes up as 0x80 which I is gold
ModelCitizen
Grafter
Posts: 46
Registered: ‎30-04-2008

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

Thanks for the reply Jim... but I'm afraid I barely understood a word of it.
The terms I have problems with are wireshark, BBYW, 0x80 & Gold.
I have a feeling that even if I did understand these terms It might not necessarily answer the question.
Does it mean that iPlayer radio is treated exactly the same as any other streaming radio, in terms of traffic shaping and bandwidth limiting?
Another salient point is that iPlayer is fine at this moment. If there is a pattern it's that iPlayers rebuffering is mainly at its worst for an hour or two in the early evening.
Cheers.
MC
itsme
Grafter
Posts: 5,924
Thanks: 1
Registered: ‎07-04-2007

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

ModelCitizen
Grafter
Posts: 46
Registered: ‎30-04-2008

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

Cheers. That app looks useful and should help me check my current clutching-at-straws theory (which is that PlusNet may not have sufficient bandwidth to the BBC content host used for the iPlayer BBC Radio 4 stream and at times when usage is highest this causes rebuffering on the Squeezebox).
MC
Plusnet Alumni (retired) _CN_
Plusnet Alumni (retired)
Posts: 385
Registered: ‎11-06-2007

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

Mmmm if its a radio stream then its a low bit rate and we have plenty of peering BW to the BBC content.  It might be via squeezebox thats the issue.  I'll have to figure out how we can test this, never used squeezebox.  If you just play it via the iPlayer interface on a PC at the same time do they both buffer?
ModelCitizen
Grafter
Posts: 46
Registered: ‎30-04-2008

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

The architecture (and pertinently the buffer) on a Squeezbox is different from that of a computer. I can run iPlayer on my laptop on my home PlusNet wireless network at the same time, listening to the same stream and it will be fine, whereas the Squeezebox iPlayer will rebuffer. However I can also run my Squeezebox on a different wireless network at a friends, or at work (tested with Nildran and Newnet) and iPlayer runs fine on it, with no rebuffering.
I am clutching at straws but the fact that rebuffering sems to be worst at certain times of day has led me to look at my ISPs bandwidth shaping and general connectivity to the BBC radio content host/partner that the BBC use for the iPlayer Radio 4 stream (which appears to be coming from IP address 212.58.249.123 at the moment, if that means anything.. and is not just some sort of proxy).
I would of course be very interested to hear from any other PlusNet Squeezebox users (www.slimdevices.com)
MC
ModelCitizen
Grafter
Posts: 46
Registered: ‎30-04-2008

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

I have used Wireshark on my laptop (which is connected wirelessly to my Netgear router) . To get it to work I had to turn off promiscuous mode (otherwise it seemed to think that my 32bit Windows XP pro was a 64bit OS). I ran a software player that emulated a Squeezebox and listened to the iPlayer Radio 4 stream. I occasionally had rebuffering issues, but nothing like as extreme as earlier in the evening.
Wireshark reports that traffic from the iPlayer source IP address (212.58.249.123) is prioritised thus:   Differentiated Services Field: 0x60
Is this to be expected?
My account is a PlusNet Broadband Your Way Option 4 with included 40GB bandwidth for which I currently pay £29.35 a month.
Any help appreciated.
MC
Community Veteran
Posts: 19,102
Thanks: 443
Fixes: 21
Registered: ‎31-08-2007

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

My understanding is that streaming traffic should be classified Gold ie 0x80 or 0x60 as mentioned at http://www.plus.net/support/broadband/troubleshooting/wireshark.shtml#queues
ModelCitizen
Grafter
Posts: 46
Registered: ‎30-04-2008

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

Ah, I see "Interactive" includes streaming services. That was not clear to me. Thanks.
This begs the question... what determines whether a stream gets classed as 0x80 or 0x60, and for me... would Radio 4 via iPlayer work on a Logitech Squeezebox at peaks times if the iPlayer stream was classed as 0x80?
At this moment I'm thinking along the lines that the problem is some sort of incompatibility between the PlusNet bandwidth shaping and the Squeezebox (wireless) network hardware or streaming protocol (slimproto).
To _CN_:  Try to get PlusNet to buy you a Squeezebox... for diagnostic purposes of course.....  better stil get them to buy you a Boom: http://www.slimdevices.com/pi_boom.html
:-)
MC
itsme
Grafter
Posts: 5,924
Thanks: 1
Registered: ‎07-04-2007

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

Have you seen this? from my understanding you have a buffer of 3 seconds which can be increased. I would suggest trying to increase the buffer to see if this improve the situation.
Community Veteran
Posts: 3,789
Registered: ‎08-06-2007

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

Not being totally  familiar with the Squeezebox this may be totally wrong.
However, it does look like that the Squeezebox traffic is being prioritised as 0x60 which is the "gold plated" queue, not the "gold" queue, which is 0x80.
This means that during times that the network is busy, the "gold plated" traffic is squeezed before the "gold" traffic.  This could certainly be the cause of your problem - as the network gets busier the lower-queued protocols are forced into using less bandwidth.  For most protocols this isn't a problem because they're not time sensitive.  However, in this case it's my opinion that the traffic is incorrectly prioritised.
Because the Squeezeplayer effectively encapsulates the iPlayer traffic, the Ellacoyas cannot identify it as such.  However, it obviously is identifying it as SOMETHING (as it's giving it a gold-plated rating, not a bronze rating which is the default for unidentified traffic)
I suspect that Carl could confirm or deny this, and hopefully get it's queue changed to Gold, or explain why this isn't feasible.
Cheers
B.
itsme
Grafter
Posts: 5,924
Thanks: 1
Registered: ‎07-04-2007

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

Is the iplayer traffic being encapulated by Squeeze Box? The IP 212.58.249.123 specied in the earlier post belong to the BBC.
James
Grafter
Posts: 21,036
Registered: ‎04-04-2007

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

The traffic is still coming from the same place, but if the Squeezebox is using a different signature, the Ellacoya will tag the traffic as something different, I would guess.
ModelCitizen
Grafter
Posts: 46
Registered: ‎30-04-2008

Re: Bandwidth shaping - Is iPlayer treated differently from other streaming media?

I am asking questions of the developers on the Slimdevices forums: http://forums.slimdevices.com/showthread.php?t=53229.
The iPlayer plugin is a bit of software that plugs into the SqueezeCenter streaming server software. This software streams audio to a number of hardware devices built by SlimDevices (now bought by Logitech).  SlimDevices/Logitech have also developed a software emulator of their hardware device(s), which can be used for testing (as i have done for this problem).
I used Netstat on the laptop hosting the software emulator playing the stream to get the IP address.
Errr... does this help?
MC