How do VM do their traffic shaping?

[ghell]

Do they use SNMP software located in the installation disk they no doubt give out to new customers nowadays, or just QoS on their end?

I ask because someone I know, and myself, have both used NTL (under various names, when I joined it was all C&W) in Guildford since before they were giving out free 56k oh so long ago. Neither of us used any kind of installation disk because they are not needed and nobody in their right mind should install anything their ISP gives them (I don't actually know if VM/NTL gives/gave out an installation disk, I assume they do/did) and neither of us have had any problems with traffic shaping. We also have rather complicated network setups that would most likely stop SNMP getting through to VM anyway. However, QoS is done without needing to enable SNMP software on the client machine, so if they were using QoS then it would shape my traffic nomater what software I installed or OS I am using.

Also, I have found reports around that people using various linux distros (Fedora is my distro of choice) have also had no problem with traffic shaping. This leads me to believe that VM are using SNMP which must be activated by their software to monitor traffic. If this is the case, the simple solution to shaping is not to install any of their crap on any of your machines.

Does anyone have any information on how VM use traffic shaping?

[handyman]

Originally Posted by ghell

Does anyone have any information on how VM use traffic shaping?

The use hardware at the headends in order to traffic shape.

[ghell]

That's pretty vague, do they use QoS to monitor and shape traffic in said hardware or what?

If that is the case, how come nomatter how much I torrent (legally, though I expect that makes no difference) I don't get any kind of performance hit?

Also, I'm not trying to actually bypass the shaping or something (I have read in other posts that, for example, Bill C can't post any details that would allow someone to bypass it) I'm just curious as to how they do it and why it affects some but not others.

Originally Posted by ghell

That's pretty vague, do they use QoS to monitor and shape traffic in said hardware or what?

If that is the case, how come nomatter how much I torrent (legally, though I expect that makes no difference) I don't get any kind of performance hit?

Also, I'm not trying to actually bypass the shaping or something (I have read in other posts that, for example, Bill C can't post any details that would allow someone to bypass it) I'm just curious as to how they do it and why it affects some but not others.

There is nothing you can do at your end to bypass it. As for how it works i would be stunned if you get that sort of information on a open forum from someone who works for Virginmedia on there broadband network.

As for it affecting some and not others That's how it should be. Affect the heavy users at peak times and allow those that surf and play games a good QOS. Then in off peak times let the leechers leech there cotton socks off.

[ghell]

Yea, I didn't expect to get the information from someone who has signed a nondisclosure agreement, but I was hoping someone might happen to know, or it might be in the public domain.

I am a heavy user, so is the other person I know, and neither of us have been affected by shaping. This is why I was saying it was affecting some (insert: heavy users) but not others.

Does it say anywhere what is affected by shaping (for example bittorrent can be detected and shaped on its own), or is it the connection as a whole, ie if you use a certain amount or are in a certain percentile of the heaviest users etc, your line speed is cut. I wouldn't have thought it would be the connection as a whole because encryption is commonly used to bypass bittorrent traffic shaping, and if it was simply based on the usage (ie dumb throttling rather than shaping) encryption wouldn't make a difference.

Doesn't the modem itself contain the bandwidth setting (but refresh it from the ISP) or is that just a theoretical maximum which the ISPs shaping can still limit.

[jules_mountain]

It's all very simple really. You access your VM service via their cable modem which is connected to your computer. The cable modem has hardware very similar to a cut down pc with its own motherboard and OS. That means that the service provider can communicate to the modem completely independently to whatever is connected in order to, amongst other things, ascertain the traffic flowing between modem and provider. In other words they don't need you to install any software on your pc, you could connect a toaster to their modem and if it used bandwith they would still be able to monitor how much!

[NotaVMFan]

Originally Posted by ghell

Yea, I didn't expect to get the information from someone who has signed a nondisclosure agreement, but I was hoping someone might happen to know, or it might be in the public domain.

I am a heavy user, so is the other person I know, and neither of us have been affected by shaping. This is why I was saying it was affecting some (insert: heavy users) but not others.

Does it say anywhere what is affected by shaping (for example bittorrent can be detected and shaped on its own), or is it the connection as a whole, ie if you use a certain amount or are in a certain percentile of the heaviest users etc, your line speed is cut. I wouldn't have thought it would be the connection as a whole because encryption is commonly used to bypass bittorrent traffic shaping, and if it was simply based on the usage (ie dumb throttling rather than shaping) encryption wouldn't make a difference.

Doesn't the modem itself contain the bandwidth setting (but refresh it from the ISP) or is that just a theoretical maximum which the ISPs shaping can still limit.

What I can make out it`s done using the Mac of the modem at the headend.

There was a manual floating about from Cisco systems detailing how the Traffic management worked.

I`ll endeavour to find the link and add it to this post...

[dev]

afaik VM don't do any traditional traffic shaping (all types of traffic have the same priority). Again, afaik, the STM is done at the headend and counts all traffic to/from your modem (whether it is requested by you or not). That amount is totalled up between 4pm and 9pm and if you hit the limit set for your speed, your speed is then dropped to the speed outlined in the STM rules.

VM would be stupid to rely on snmp as most firewalls would probably block it and would require running at least another process, not to mention working out if it was local traffic or not.

[moaningmags]

Very few people actually use the disk.
I've never used it in the 8 yrs I've been a customer and in
almost 3 years doing tech support, I always get the customer
to cancel the install disk.
So relying on the disk to traffic manage people is useless.

[Stuart]

Originally Posted by NotaVMFan

What I can make out it`s done using the Mac of the modem at the headend.

There was a manual floating about from Cisco systems detailing how the Traffic management worked.

I`ll endeavour to find the link and add it to this post...

You do realise you have ressurected a thread that is nearly a year old?

---------- Post added at 01:11 ---------- Previous post was at 01:09 ----------

Originally Posted by dev

VM would be stupid to rely on snmp as most firewalls would probably block it and would require running at least another process, not to mention working out if it was local traffic or not.

They wouldn't need to access your computer for the snmp protocol to work. All they would need would be for the modem to answer any queries. Seeing as the modem should be connected between your firewall or router and Virgin's network, the query wouldn't even reach your firewall.

[NotaVMFan]

[QUOTE=Stuart C;34491780]You do realise you have ressurected a thread that is nearly a year old?

---------- Post added at 01:11 ---------- Previous post was at 01:09 ----------


You need to goto Specsavers

It was Jules who ressurected the thread..

I would like to see how they do this but never will hopefully they will remove it soon but I dont really get that affected by it thanks to lovely utorrent setting been tweaked

[dav]

Originally Posted by darthlinux

I would like to see how they do this but never will hopefully they will remove it soon but I dont really get that affected by it thanks to lovely utorrent setting been tweaked

I'm intrigued.

Could you elaborate if it doesn't just involve scheduling?

[jcuk]

STM is brought into effect at the CMTS on the UBR. This is done at Layer 2 Level - MAC.

Traffic is monitored, Amount of bandwidth is measured between the modems MAC address and the CMTS it is connected to. Assuming this is the case, then rebooting your cable modem may enable you to connect to another CMTS and bypass the STM - but im sure VM Techs arent that stupid, so the information would be centrally logged on the UBR.

As soon as you reach the D/l Amount during the peak times, which are 4-12pm. Then STM is triggered for the corresponding MAC Address. It does not send a new config down to the cable modem, its just altered at the CMTS for that specific MAC entry.

This is my understanding, which means the only way to bypass it would be going down to the UBR location, breaking into the building, wiring upto a terminal and modifying the MAC Tables at L2.

Id doubt STM is controlled any higher than Layer 2 MAC, simply because above this, IP's are dynamically assigned, so you would end up bypassing with a simple reboot.

Thats my views anyway.

Only way your gonna get a true answer is if your working within our Networks team.

NB : Im under the impression QoS is at Layer 3, but could be wrong, someone with more experience could post up on QoS.

Originally Posted by dav

I'm intrigued.

Could you elaborate if it doesn't just involve scheduling?

scheduling is all I meant

---------- Post added at 22:45 ---------- Previous post was at 22:45 ----------

Originally Posted by jcuk

STM is brought into effect at the CMTS on the UBR. This is done at Layer 2 Level - MAC.

Traffic is monitored, Amount of bandwidth is measured between the modems MAC address and the CMTS it is connected to. Assuming this is the case, then rebooting your cable modem may enable you to connect to another CMTS and bypass the STM - but im sure VM Techs arent that stupid, so the information would be centrally logged on the UBR.

As soon as you reach the D/l Amount during the peak times, which are 4-12pm. Then STM is triggered for the corresponding MAC Address. It does not send a new config down to the cable modem, its just altered at the CMTS for that specific MAC entry.

This is my understanding, which means the only way to bypass it would be going down to the UBR location, breaking into the building, wiring upto a terminal and modifying the MAC Tables at L2.

Id doubt STM is controlled any higher than Layer 2 MAC, simply because above this, IP's are dynamically assigned, so you would end up bypassing with a simple reboot.

Thats my views anyway.

Only way your gonna get a true answer is if your working within our Networks team.

NB : Im under the impression QoS is at Layer 3, but could be wrong, someone with more experience could post up on QoS.

STM time frame is 4-9pm not 4-12pm change a month ago.

check the STM page