Home News Forum Articles
  Welcome back Join CF
You are here You are here: Home | Forum | SM4 area very poor performance


You are currently viewing our boards as a guest which gives you limited access to view most of the discussions, articles and other free features. By joining our Virgin Media community you will have full access to all discussions, be able to view and post threads, communicate privately with other members (PM), respond to polls, upload your own images/photos, and access many other special features. Registration is fast, simple and absolutely free so please join our community today.


Welcome to Cable Forum
Go Back   Cable Forum > Virgin Media Services > Virgin Media Internet Service

SM4 area very poor performance
Reply
 
Thread Tools
Old 12-03-2012, 22:55   #16
qasdfdsaq
cf. mega noob
 
qasdfdsaq's Avatar
 
Join Date: Aug 2004
Posts: 8,904
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
Re: SM4 area very poor performance

Ignition would know

Based on recent events it would seem a particular CMTS has lots of line cards and lots and lots of gigabit ethernet ports. Making distinctions on the CMTS level aren't really useful. Links from the CMTS to the core are rarely if ever congested, because there is so much more of it than capacity from the CMTS to the end user.

What you really want to look at is line cards and congestion at that level. There may be multiple line cards serving an optical node and subcabinets from there. Not every customer on any given cabinet will be connected to any given line card, a line card's capacity may be spread over several cabinets, and have several line cards serving each cabinet. How granular this actually gets I don't know. But it's not the case where everyone on one cabinet => one set of capacity.
__________________
Ultimate® SuperHub2™ Mod©:
N750 Simultaneous dual-band wireless (300+450)
5 Upgradeable antennas, dual-processor, 7 ports
Fully customizeable dd-wrt/openwrt routing engine
qasdfdsaq is offline   Reply With Quote
Advertisement
Old 12-03-2012, 23:19   #17
ccarmock
cf.addict
 
Join Date: Jun 2008
Posts: 418
ccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to all
Re: SM4 area very poor performance

Interesting - thanks for that. How is the mapping for a given customer to line card done?

I had assumed that a given line card and port would provide a given set of 4 downstreams (or more when enabled) that all modems would connect to on cabinets served by that port.

Or should I think more in terms that a given port on a line card will generate a set of downstreams and several sets of downstreams map to a given node and cabinets and the modems config files determine which is used?

If this latter way is the method would it not be possible to change the line card a given user mapped to by changing a config file?
ccarmock is offline   Reply With Quote
Old 12-03-2012, 23:37   #18
qasdfdsaq
cf. mega noob
 
qasdfdsaq's Avatar
 
Join Date: Aug 2004
Posts: 8,904
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
Re: SM4 area very poor performance

Just noticed the base ping on your TBB graph - your traffic is taking a very roundabout route, via Manchester. Your base ping should be <8ms. It's only affecting a few routes though, so not a significant part of the bigger problem
__________________
Ultimate® SuperHub2™ Mod©:
N750 Simultaneous dual-band wireless (300+450)
5 Upgradeable antennas, dual-processor, 7 ports
Fully customizeable dd-wrt/openwrt routing engine
qasdfdsaq is offline   Reply With Quote
Old 12-03-2012, 23:50   #19
ccarmock
cf.addict
 
Join Date: Jun 2008
Posts: 418
ccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to all
Re: SM4 area very poor performance

This is because I have the Virgin Media Business servcie with a subnet of public IP addresses (6 in fact). In order to achieve that the business Superhub (same hardware different firmware) forms an L2TP tunnel into the VM network so that it can obtain truely static IP addresses. This means that all traffic has to traverse this tunnel and breakout from the core of the network.

So I tarcert to www.bbc.oc.uk looks a bit different on this service:-

C:\>tracert www.bbc.co.uk

Tracing route to www.bbc.net.uk [212.58.246.94]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms gw [10.10.1.1]
2 46 ms 61 ms 48 ms brad-bam-1.network.virginmedia.net [194.145.148.
188]
3 42 ms 37 ms 42 ms brad-core-1b-ge48.network.virginmedia.net [213.1
05.159.42]
4 49 ms 84 ms 18 ms brad-core-2b-ae2-0.network.virginmedia.net [212.
43.163.237]
5 26 ms 43 ms 35 ms leed-bb-1b-ae6-0.network.virginmedia.net [81.97.
80.121]
6 55 ms 38 ms 51 ms leed-bb-1a-ae0-0.network.virginmedia.net [62.253
.187.185]
7 32 ms 70 ms 69 ms nrth-bb-1b-as2-0.network.virginmedia.net [62.253
.185.101]
8 34 ms 23 ms 31 ms tele-ic-4-ae0-0.network.virginmedia.net [62.253.
174.18]
9 43 ms 64 ms 33 ms pos6-1.rt0.thdo.bbc.co.uk [212.58.239.237]
10 * * * Request timed out.
11 68 ms 94 ms 32 ms ae0.er01.cwwtf.bbc.co.uk [132.185.254.93]
12 29 ms 39 ms 63 ms 132.185.255.165
13 102 ms 88 ms 32 ms bbc-vip015.cwwtf.bbc.co.uk [212.58.246.94]

Trace complete.

Notice the first hop after the local router isn't the local CMTS at all but the distant end of the L2TP tunnel.

I agree though that the base latency is higher than I hoped on this service.
ccarmock is offline   Reply With Quote
Old 13-03-2012, 00:18   #20
qasdfdsaq
cf. mega noob
 
qasdfdsaq's Avatar
 
Join Date: Aug 2004
Posts: 8,904
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
Re: SM4 area very poor performance

That's not it though - I'm tracing to the raw IP (the one you PM'd me) of the Superhub itself - from one location (my NL datacentre) it takes the following route:

traceroute to <snip>, 30 hops max, 60 byte packets
1 hosted.by.leaseweb.com (95.211.44.252) 0.494 ms 0.565 ms 0.609 ms
2 te4-3.sr1.evo.leaseweb.net (85.17.129.209) 0.592 ms 0.634 ms 0.735 ms
3 te5-2.sr2.evo.leaseweb.net (85.17.129.194) 0.528 ms 0.606 ms 0.708 ms
4 be12.crs.tc2.leaseweb.net (62.212.80.73) 0.696 ms 0.921 ms 0.902 ms
5 195.69.145.253 (195.69.145.253) 11.247 ms 11.699 ms 11.209 ms
6 manc-bb-1a-ae9-0.network.virginmedia.net (62.253.188.157) 20.775 ms 20.528 ms 39.580 ms
7 popl-bb-1b-as3-0.network.virginmedia.net (62.252.192.158) 28.069 ms 28.051 ms 18.474 ms
8 croy-core-2b-ae0-0.network.virginmedia.net (81.96.226.6) 28.433 ms 19.399 ms 18.723 ms
9 croy-core-1b-pc200.network.virginmedia.net (195.182.178.85) 29.164 ms 18.789 ms 19.245 ms
10 nmal-geam-1b-pc112.network.virginmedia.net (62.30.242.54) 29.149 ms 28.859 ms 27.891 ms
11 nmal-cmts-18-ge330.network.virginmedia.net (81.96.225.198) 27.873 ms 35.660 ms 35.740 ms
(and then times out)

Whereas a trace from my London datacentre goes the sensible way:
traceroute to <snip>, 30 hops max, 60 byte packets
1 ge-0-0-5-4.cs0.thw.uk.goscomb.net (93.89.92.1) 1.301 ms 2.173 ms 2.011 ms
2 xe-0-0-0.rt0.the.uk.goscomb.net (93.89.91.13) 40.619 ms 40.347 ms 40.243 ms
3 tele-ic-5-xe-020-0.network.virginmedia.net (62.253.174.69) 0.519 ms 0.420 ms 0.309 ms
4 popl-bb-1b-ae12-0.network.virginmedia.net (213.105.159.118) 0.554 ms 0.445 ms 0.346 ms
5 croy-core-2b-ae0-0.network.virginmedia.net (81.96.226.6) 1.231 ms 1.007 ms 0.897 ms
6 croy-core-1b-pc200.network.virginmedia.net (195.182.178.85) 1.624 ms 1.418 ms 1.774 ms
7 nmal-geam-1b-pc112.network.virginmedia.net (62.30.242.54) 2.084 ms 2.022 ms 2.020 ms
8 nmal-cmts-18-ge334.network.virginmedia.net (81.96.225.214) 1.859 ms 1.869 ms 1.744 ms^C

Anyway, I don't think the routing's at fault for once.
__________________
Ultimate® SuperHub2™ Mod©:
N750 Simultaneous dual-band wireless (300+450)
5 Upgradeable antennas, dual-processor, 7 ports
Fully customizeable dd-wrt/openwrt routing engine

Last edited by qasdfdsaq; 13-03-2012 at 00:23.
qasdfdsaq is offline   Reply With Quote
Old 13-03-2012, 00:22   #21
ccarmock
cf.addict
 
Join Date: Jun 2008
Posts: 418
ccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to all
Re: SM4 area very poor performance

Hi,
The raw IP will take the normal route (ie no via the L2TP tunnel). I have PMd you the IP that traffic actually uses....
ccarmock is offline   Reply With Quote
Old 13-03-2012, 00:52   #22
qasdfdsaq
cf. mega noob
 
qasdfdsaq's Avatar
 
Join Date: Aug 2004
Posts: 8,904
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
Re: SM4 area very poor performance

Yeah, as I said, the "normal" route without the tunnel is still going via Manchester for some sources... Odd.

In any case I've drawn up a script that pings every (VM) IP in New Malden in turn and calculats jitter on it. It's a dirty hack but I'm going to leave it running overnight to see if I can localize the problem.
__________________
Ultimate® SuperHub2™ Mod©:
N750 Simultaneous dual-band wireless (300+450)
5 Upgradeable antennas, dual-processor, 7 ports
Fully customizeable dd-wrt/openwrt routing engine
qasdfdsaq is offline   Reply With Quote
Old 14-03-2012, 00:47   #23
ccarmock
cf.addict
 
Join Date: Jun 2008
Posts: 418
ccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to all
Re: SM4 area very poor performance

thanks - I'll be interested in your thgouhts
ccarmock is offline   Reply With Quote
Old 14-03-2012, 00:49   #24
qasdfdsaq
cf. mega noob
 
qasdfdsaq's Avatar
 
Join Date: Aug 2004
Posts: 8,904
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
Re: SM4 area very poor performance

Almost exactly 24 hours on, I'm still half asleep and haven't had a chance to look at it yet - sorry.
__________________
Ultimate® SuperHub2™ Mod©:
N750 Simultaneous dual-band wireless (300+450)
5 Upgradeable antennas, dual-processor, 7 ports
Fully customizeable dd-wrt/openwrt routing engine
qasdfdsaq is offline   Reply With Quote
Old 14-03-2012, 22:01   #25
ccarmock
cf.addict
 
Join Date: Jun 2008
Posts: 418
ccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to all
Re: SM4 area very poor performance

Things seem much better tonight in this area. I had escalated this to the CEO's office and have a person checking this out for me. She tells me that IP edge planning have been told to prioritise the work and that a planner was assigned to work on this yesterday with a likely implementation by Friday.

Anyway I have noticed that at periods of high congestion the superhub's top blue light will stop flashing and stay on solid blue. Sometimes if the congestion is very prolonged it won't recover and requires a reboot.

Now tonight speeds were fine but the blue light stayed on solid resuting in no internet access. rebooting fixed it. However I don't think there was congestion tonight.

I am wondering if there is a fault with this Superhub.... has anyone else seen the blue light stay on solid?

Also I note that the upstream channel has changed - it was always ch2 before but for the first time it has changed to Ch5 after the reboot.
ccarmock is offline   Reply With Quote
Old 14-03-2012, 22:26   #26
qasdfdsaq
cf. mega noob
 
qasdfdsaq's Avatar
 
Join Date: Aug 2004
Posts: 8,904
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
Re: SM4 area very poor performance

On the Superhub? No - I don't use one. But on the VMNG300 I frequently saw similar behaviour, where all the blue lights would stop flashing and stay steady blue. Usually required a reboot, also occurred more often when the network was more congested (month-wise not hour-wise though)

Oh, and had a look at the ping figures for New Malden a few nights ago (which I probably should have just left running 24/7). 2166 responding IPs.

Mean jitter was 9.8ms, median 9.3, 57 people had 2ms or less. Yours is currently ~9.6, which ain't too bad. Can't remember what it was two days ago though.
__________________
Ultimate® SuperHub2™ Mod©:
N750 Simultaneous dual-band wireless (300+450)
5 Upgradeable antennas, dual-processor, 7 ports
Fully customizeable dd-wrt/openwrt routing engine

Last edited by qasdfdsaq; 14-03-2012 at 22:51.
qasdfdsaq is offline   Reply With Quote
Old 14-03-2012, 22:37   #27
ccarmock
cf.addict
 
Join Date: Jun 2008
Posts: 418
ccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to all
Re: SM4 area very poor performance

Interesting - thanks so it maybe that it's a 'feature' of these devices then as opposed to a bug. Seems more frequent these days, and as you say seems to coincide with congestion, though that wasn't the case tonight when it went solid blue.

I also see sometimes when i go to http://192.168.0.1 I get a partial login page - the icons are not there but the username & password boxes are. It will never allow me to login when that happens, but if I want 30 mins I can then login OK, as if something times out.
ccarmock is offline   Reply With Quote
Old 14-03-2012, 23:04   #28
qasdfdsaq
cf. mega noob
 
qasdfdsaq's Avatar
 
Join Date: Aug 2004
Posts: 8,904
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
Re: SM4 area very poor performance

Curious. I don't see it as a feature, I see it as my modem crashing... However VM always quietly sidestepped the question when I asked if it was possibly a faulty modem, and always blamed it on the congestion.

Anyhow, some charts for your perusal:





You should probably subtract ~15ms from your pings to account for the fact it's going through Manchester and back
__________________
Ultimate® SuperHub2™ Mod©:
N750 Simultaneous dual-band wireless (300+450)
5 Upgradeable antennas, dual-processor, 7 ports
Fully customizeable dd-wrt/openwrt routing engine
qasdfdsaq is offline   Reply With Quote
Old 15-03-2012, 21:41   #29
ccarmock
cf.addict
 
Join Date: Jun 2008
Posts: 418
ccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to allccarmock is a name known to all
Re: SM4 area very poor performance

Well I had an email from the person looking into my complaint in VMB today to say relief work was carried out at 9:15 this morning.

I was sent a graph showing number of devices on each of the 4 upstreams on the CMTS I am on. US 0 & 1 were showing 200 users each and US 3 & 4 100 each on average then at 9:15 US 1 dropped to 100 users.

I guess they moved 100 users to a totally different CMTS since neither of the upstreams showed an increase to ofset those moved. They left US 0 at 200 users though.

My issue was downstream congestion though, but VM always seem to focus on upstream for some reason.

So far tonight it is much better though.
ccarmock is offline   Reply With Quote
Old 15-03-2012, 21:51   #30
qasdfdsaq
cf. mega noob
 
qasdfdsaq's Avatar
 
Join Date: Aug 2004
Posts: 8,904
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
qasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze arrayqasdfdsaq has a bronze array
Re: SM4 area very poor performance

Difference is downstream channels are bonded and upstream aren't.

Oddly I'm seeing 19ms jitter on your line atm, i.e. more than yesterday, how's your thinkbroadband graph looking?
__________________
Ultimate® SuperHub2™ Mod©:
N750 Simultaneous dual-band wireless (300+450)
5 Upgradeable antennas, dual-processor, 7 ports
Fully customizeable dd-wrt/openwrt routing engine
qasdfdsaq is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Google Search




All times are GMT +1. The time now is 03:02.


Server: titan.cableforum.co.uk
Powered by vBulletin® Version 3.8.9 Beta 1
Copyright ©2000 - 2014, vBulletin Solutions, Inc.


SEO by vBSEO 3.3.2