The main Plusnet Central Pipes Information page was getting a bit full and hard to read because of its length, therefore Ive shufted some of the historic information here.

Pipe Selection.

BT use the "round robin" method of selecting which pipe you will be connected to when you log onto their network. That means each user is connected to a particular pipe in rotation.
Unfortunately, this method has recently caused some problems as some pipes have been more loaded than others.

The reason being is that each 155Mb pipe has 2 tunnel end points... whilst each 155Mb segment of a 622Mb pipe has 3 end points, therefore the Redbacks have been occasionally more loaded than the Junipers.
The problem can easily be resolved by disconnecting and reconnecting on another pipe.

There are talks that a resolution may be to transferring to all 622Mb pipes, and Plusnet are currently in discussion with BTw to resolve this issue.

Dec 2004:- 155's -v- 622's

BTw's method of load balancing the various pipes has meant that some users on certain pipes have seen slight slow-downs. This issue is being looked at by PN and BT and a solution proposed that the Redbacks will be made redundant and all 622's and Junipers will be installed. The upgrade progress will take approximately 6 to 12 weeks to be completed.

Feb 2005:- 155's -v- 622's

The process of installing 2 more 622Mb pipes and a Juniper at Telehouse East commenced. 14th of Feb saw the 622 pipes go live and the users on Redback 1 moved over to the new pipes. Redback 1 is to be set up as a fall-over unit for the new Juniper.

The ERX's have subscriber session limits and Juniper are releasing new firmware which will support a greater number later in the year. Until then the the SMS10ks will terminate some sessions on behalf of the ERX's until the firmware is updated.

The 155Mb pipes were decommissioned on the 18th of Feb.

Jun 2005:- 155's -v- 622's

Work in Progress to decommission Redback 2 as an overspill device for Juniper 3 which currently has 2 x 622 pipes. Juniper 4 will take over one of the 622's from Juniper 3.

It is thought that the 2 Redbacks will be utilised as backup devices for the Junipers.

Sep 2005 - Historical Peak Utilisation Figures.

For about a year I kept an eye on Plusnets Utilisation figures and recorded peak time capacity.
Unfortunately in September 2005 Plusnet withdrew the old style utilisation graphs from which I gained peak capacity, therefore I am no longer able to monitor these figures.

However, I've kept the tables for historical information and these can be viewed from here.

Feb 2005 - Plusnet Contention Ratio

In Feb 2005 I performed the following calculation based on information to hand that time:-

4 x 622Mbps = 2488Mb available bandwidth. Customer Base = 100,000. % Figures obtained from Plusnet.

65.97% of users on 512k = 65,970
24.33% of users on 1024k = 24,330
9.69% of users on 2048k = 9,690

Total possible peak bandwidth

32,985 (512s)
24,330 (1Mbs)
19,380 (2Mbs)
76,695 Mbps (total)
/ 2488

= 30.83:1

Feb 2006 - Plusnet Capacity Report

Report on the state of Plusnet Centrals - cut down version Wholesale cost of adsl in the UK

July 2006 - Decommissioning of Plusnet 1

I'm not exactly sure what happened here and the exact timescale, but Plusnet decommissioned a complete central?

May 2008 - MAAF / Brightview Group Amalgamation.

All segments on PlusNet 8 are lit, 2 1/3rd of the segments are allocated to PlusNet customers (and new MAAF signups) and 1 2/3rd segments are allocated to existing (rather than new) MAAF customers and the other MAAF-related realms.

July 2009 - Lots of pipes?

The past year has seen a flurry of new pipes consistently lit.. but there appears to be a new pipe Plusnet 12 hooked up to an existing juniper. No info released via SS, but this also seems to coincide with some changing around with the MAAF/Brightview centrals and 4 new Cisco 7301

Old Addresses

Historically, the 155 pipes terminated on two Redback SMS10000 aggregators, commonly known as the Redbacks. Each Redback had 5 central pipes and were located at Telehouse East.

* The ERX's have subscriber session limits and Juniper are releasing code which will support a greater number later in the year. In the meantime the SMS10ks will terminate a fair number of sessions on behalf of the ERX's until PN can deploy the code.

Redback 1 was is use DSLconnect customers but these customers have now been amalgamated onto the Junipers. I have recently seen an instance whereby it is possible that Redback 1 was now also being used as an overspill device.

Traffic

PAYG Traffic

Premier Traffic
(suspect this may now be recording something else wef Jun 06)

BroadBand Plus Traffic

Packets Dropped

Traffic Type

Official Plusnet Utilisation Graphs