Kitz Forum

Broadband Related => ISPs => Topic started by: jid on April 23, 2009, 05:02:50 PM

Title: Tiscali Outage Resolution
Post by: jid on April 23, 2009, 05:02:50 PM
http://www.tiscali.co.uk/forums/showthread.php?p=2172085

Some people who are still having problems connecting to Tiscali may want to have a read of this.
Title: Re: Tiscali Outage Resolution
Post by: Oranged on April 23, 2009, 05:36:41 PM
That reminds me of my days with Orange......it occurred quite regularly on LLU....anybody know what causes it ?.....sorry I'll expand that, I realise it's probably to do with someone doing something incorrectly with server or exchange equipment settings but what exactly ?
Title: Re: Tiscali Outage Resolution
Post by: kitz on April 23, 2009, 06:53:37 PM
Quote
Someone changed something in exchange! Without telling me that I should change encapsulation to PPPoE and multiplexing to LLC in my router

I dont know whether to laugh or cry either.  That solution is so simple and its something that the Tiscali reps should be advising as a matter of course... This has been well known and documented for years.

The cause - the line has suddenly been LLU'd. 
BTw dsalms are configured to accept either LLC-Based or VC-Mux, whilst the Tiscali MSANs will only accept VC-Mux.

The PPPoE bit is irrelevant. 
It should be PPPoA for tiscali too, as the back link from the exchange is still ATM.  Setting it at PPPoE will only cause the MSAN to emulate PPPoE (PPPoEoA) which will cause additional overheads, and actually slow down the throughput speed.
AFAIK in the UK,  theres only Be/O2 LLU  where it should be set anything other than PPPoA.

Title: Re: Tiscali Outage Resolution
Post by: kitz on April 23, 2009, 06:58:06 PM
That reminds me of my days with Orange......it occurred quite regularly on LLU....anybody know what causes it ?.....sorry I'll expand that, I realise it's probably to do with someone doing something incorrectly with server or exchange equipment settings but what exactly ?

Partially explained above due to the type of adsl settings used in the UK, but some routers are set/shipped as 'Auto-configure' or LLC based. 

BT Wholesale dslams/msans are configured to accept various types of connections... and they also have them set up so that if your router is set at auto-configure the router wont be going round and round chasing with the dslam to get the correct setting.
Just say that BTw have covered all bases to try an make user set up as painless as possible.


So if and when a line is LLU'd, what settings would work on the BTw DSLAMs,  no longer work with the LLU ones... and its just a matter of making sure the router is set to VC-Mux.

In fact, this is what BTw have to say
Quote
BT IPstream presents a Protocol and encapsulation auto-sensing PPP layer over the ATM.  The following combinations of protocol and encapsulations are supported:-

  PPPoA VC-mux,
  PPPoA LLC/SNAP
  PPPoE LLC/SNAP - single session per VC (ADSL line) only.

The BT IPstream BAS will automatically configure itself to the protocol presented by the End User’s CPE.  Some CPE is itself auto-sensing – in order to ensure that the BAS and CPE do not constantly chase each other, changing protocols and encapsulations, the BAS implements a minimum time period before which it will change encapsulation. Following an encapsulation change the BAS always starts by requesting the creation of a PPPoA session.


The following RFC describe the Protocols and encapsulations used:
  RFC 1483[13] – Multi-Protocol encapsulation
  RFC 1661[7] – PPP
  RFC 2364[6] – PPP over AAL5 (ATM)
  RFC 2516[14] – PPP over Ethernet

The BT IPstream 500 and BT IPstream S Series products use PPPoA with VC-mux encapsulation. It should be noted that the use of LLC/SNAP and PPPoE incur a higher protocol overhead and therefore will provide a lower throughput than the use of PPPoA/VC-mux.



Title: Re: Tiscali Outage Resolution
Post by: stevie on April 23, 2009, 07:04:30 PM
I pointed to the same link in a post on TBB...following a post be Brett.  ;D

http://forums.thinkbroadband.com/tiscali/f/3620006-tiscali-still-having-issues.html

I do wonder about Tiscali & sometimes more so about some of their customers?

Some of their customers have some serious patience... :o
Title: Re: Tiscali Outage Resolution
Post by: kitz on April 23, 2009, 09:23:57 PM
Indeed they must :/
Title: Re: Tiscali Outage Resolution
Post by: jid on April 23, 2009, 09:34:59 PM
Indeed they must :/

Look at me :lol:

LLU'd they must have been:D

They are up to their famous tricks again lol.