Pings

[maxping]

Simon phoned me tonight and assured me this ping issue is being investigated . He also suggested phoning Miriam to find out if Interleaving may have been turned on by mistake, this would explain my problem so i will phone tomorrow and keep my fingers crossed.



Latency and Interleaving

(This was news posted a while ago, 2000-05-16 18:11:52 to be exact.)
Written by Justin


For internet telephony or interactive applications such as remote administration over a telnet session, latency is a key (and much discussed) attribute of the connection.

At the moment, the class of users most obsessed with latency would have to be the online gaming community. They are often buy entry level residential ADSL lines, with high download speeds, and are dismayed to read that friends on slower SDSL or IDSL lines are getting better ping times!

The first reaction of a disappointed gamer is to blame the ISP for routing inefficiencies or congestion, and although that is often the root cause, there is more to latency than just many hops and/or long distances.

ADSL modems commonly employ data Interleaving, which is a technique to increase resistance to noise bursts on a line. Interleaving "smears" out micro bits of data (interleaves them over time) so that a short burst of signal destroying noise can only remove part of any given larger block. Data blocks reserve some space for error-correction data.. which can salvage a partially damaged block. Interleaving increases the chance that noise on the line will only cause partial damage, not complete loss. Thats the good news.

The down-side of Interleaving is that it increases latency! this is because your little (say) quake movement packet is smeared out over several packets before it can be fully sent or fully received.

ADSL modems with typical Interleaving defaults can be 10-30ms behind in latency over equivalent speed SDSL modems... this means latency to any point for some ADSL modems can be at best 50ms! On the same setup, the aforementioned SDSL modems that typically add only 10ms. So for use of a nearby server, ADSL Interleaving can be the biggest single source of latency that you have.

Unfortunately, there is little clear information supplied with, or available online, about what latency a given DSL modem or ISP connection has built-in.

Some ADSL modems allow the user to turn off Interleaving, or turn it down to a narrow range, at the expense of possible data-loss on noisy lines. The Cisco 675, for example, has a full operating system inside it, and one of the attributes of the ether interface is Interleaving. See Randy Lutton's US West page). Some ISPs may be delivering this unit with Interleaving on, and some off. In other cases, it is the DSLAM (central office equipment) that has the Interleaving set, and this cannot be changed.

If you want to read more about Latency, then we can recommend this paper by Stuart Cheshire, which was published back in 1996 but is totally relevant now.

[Bill]

That article is 6 years old....things have changed.

It indicates that it's the modem (routers don't seem to get a mention...) that uses interleaving- not so. The DSLAM at the exchange determines this, and your modem or router had better follow suit or else...

Where it acknowledges that the DSLAM may set it on or off, it states that it cannot be changed- rubbish. Though I'll concede that it can't be changed by the user.

It says that there is little information about whether the ISP has turned interleaving on or off- rubbish.

Where did you get that article?

[maxping]

Bill i Googled it, it may be out of date but i was trying to show people how interleaving can cause problems if its switched on.

Could anyone Reading this do us a favour and do a quick ping test.

I'm asking because most non gamers probably never realise how high or low their pings are , i would like to know if its just a few of us that are effected or the majority.

If you have XP hit start/progs/accessories & click on command prompt.

A black box will open and you will see the cursor flashing , type ping -t www.idnet.net and hit enter ,let it run for 30 seconds then tell us the lowest and highest you get.



Thanks in advance.

[sobranie]

Lowest 25
Highest 31
Over 4 minutes

[AvengerUK]

my pings are 100% fixed, nice one idnet!

[maxping]

Lowest 25
Highest 31
Over 4 minutes

Mine =

Lowest  - 47

Highest  - 61

Running approx 2 mins.

[maxping]

my pings are 100% fixed, nice one idnet!

You have a pm 

[golden]

  mine =

   lowest   - 23

  highest   - 28

  average - 24

  over 2 mins


richard

[maxping]

Thanks all keep them coming.

[Danni]

Lowest = 43ms
Highest = 72ms

Over about 2 minutes. 2 spikes, one of 65ms, the other 72ms.

At some point I might ask about getting interleaving turned off, since we're playing more online games now...

[maxping]

Thanks Danni,

I was supposed to phone Miriam after work Friday as Simon thought interleaving may have been turned on ,  i totally forgot - DOH .

After a bit of Googling i found out my router may tell me if its on or off ,  it does (see below) so it looks like its been turned on for some reason, it must have been off until a couple of weeks ago as my pings were a lot lower than they are now. 

I'm just happy i can get it turned off and things should go back to normal. 

[maxping]

Simon check your pm's 


A bit more info on the effects of having interleaving turned on for those interested.


The concerns that some of you have raised are that there will be an increase in Lag on the line should interleaving be applied. This is true because the process of buffering the data bits and reordering them can add anything between 5ms and 20ms onto the time. This is also only in one direction, data travel in 2 directions, Tx and Rx. So this will mean that it could realistically add 10ms to 40ms on the round trip time.

It is also important to note that the time is not random it depends on the make of the DSLAM, some manufacturers kit can do this process in a shorter time than others. BT Wholesale does not have one supplier of equipment so we can not say what the effect will be on each line.

Having interleaving on will increase the line stability, there will be less likely hood of dropped connections or slow speeds, but it does increase your response times which gamers may not want.

[johndh]

Pings:

Lowest 25ms

Highest 35ms**

**Every 60-65 seconds 500ms spike

Cheers

[equk]

--- www.idnet.net ping statistics ---
90 packets transmitted, 90 received, 0% packet loss, time 89647ms
rtt min/avg/max/mdev = 19.439/28.556/56.080/8.769 ms

[equk]

would interleaving increase your bandwidth usage much 
was just thinking if duplicate packets get sent surely your download speeds would decrease and your bandwidth usage would increase
or does it not effect things to that extent

[maxping]

It wont be effecting mine come Weds 

[Bill]

would interleaving increase your bandwidth usage much 
was just thinking if duplicate packets get sent surely your download speeds would decrease and your bandwidth usage would increase
or does it not effect things to that extent

I'd guess that in theory you're right, but if your connection gets that bad, the extra traffic is going to be the least of your worries!

[CatMangler]

Is there something happening at IDnet I should know about?

My pings have shot up enormously!!

C:\Documents and Settings\Administrator>tracert idnet.co.uk

Tracing route to idnet.co.uk [212.69.36.10]
over a maximum of 30 hops:

  1    <1 ms    <1 ms    <1 ms  192.168.0.1
  2   135 ms   132 ms   120 ms  telehouse-bb-gw1-vpdn.idnet.net [212.69.63.45]
  3   407 ms   135 ms   120 ms  telehouse-gw.idnet.net [212.69.40.1]
  4   120 ms   127 ms   129 ms  redbus-gw-fa0-0-1003.idnet.net [212.69.63.1]
  5   111 ms    97 ms   106 ms  www.idnet.net [212.69.36.10]

Trace complete.

[equk]

Just had the same playing on quake3, very unstable ping of 50-60 next min it was 150   pay for adsl for gaming and end up with this 

[CatMangler]

Ok, so its not just me then.

EDIT:

Some ping stats to illustrate:

Ping statistics for 212.69.36.10:
    Packets: Sent = 470, Received = 461, Lost = 9 (1% loss),
Approximate round trip times in milli-seconds:
    Minimum = 106ms, Maximum = 205ms, Average = 143ms

[philco]

Yeah, today is not to good for me again.

[attachment deleted by admin]

[mrapoc]

jeeez man i was just playing cs ON A LONDON BASED SERVER and i was getting pings average about 170 and topping 200  it was utterely unplayable! Even the foreigners had lower pings around 50-70! While doing a server search the lowest i could find was 145 which is 1 of my favourites where i  used to get pings of around 15 

Its strange i either get a way too low ping of like 2-5 or i get a monster of a ping 170+

[maxping]

Try giving customer support a call, as you know for some reason interleaving (*sp) has been activated on my line and my pings are higher than they were.

Its being switched off in the next 24 hours thanks to Miriam.

[CatMangler]

It would appear that stablility has returned:

Ping statistics for 212.69.36.10:
    Packets: Sent = 244, Received = 244, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 12ms, Maximum = 97ms, Average = 18ms

Shame that the wife & kids are home now no gaming for me 

Must be bad karma man

Has Idnet got a handle on what the problem was? I take it everyone else is ok now?

[philco]

same, here. About 5.30pm - 5.45pm things are well again. About the same time every day.