In reply to a post by Icaras:

It's mandatory and is one of the tests that the engineers are marked and graded on for SFI jobs.

@revk definitely thinks it isn't mandatory. His further implication is that it isn't even optional!

"SFI2 is a broadband support product that tests to voice standards."

Certainly the BTWholesale Knowledge Based Diagnostics test will check most of what you've listed there. I believe they pick up something like 90% of faults for ADSL and over 95% for FTTC (this is probably higher now as tests have improved).

Most ISPs book a SFI visit when the KBD tests come back showing no fault detected. It's therefore, in most cases, a performance issue rather than a specifically clear fault.

I don't think the issue is as such Openreach and SFI, but more BT Wholesale and they way they handle performance issues or faults that they've been unable to identify with their KBD.

Edit: I should add here that you some very experienced and knowledgable support staff working at niche ISPs (like AAISP) who quite frankly, know a lot more than their support contacts within BT Wholesale. I suspect quite a lot of the BT Wholesale front line support staff have limited ISP and carrier level network training and understanding. This clearly creates an issue when an ISP has definitive evidence of a network fault (and its location) and at the same time the BT Wholesale Support staff member is unable to understand or input that fault into the system.

If you look at RevK's latest post http://www.revk.uk/2017/01/teaching-us-to-suck-eggs-... this shows a classic example of this. There will be some very experienced and knowledgeable within Openreach that AAISP could work with to resolve this, but the problem is the system and protocol from BT Wholesale does not allow this.

Edited by deleted (Tue 17-Jan-17 12:29:02)

In reply to a post by WWWombat:

In reply to a post by Icaras:

It's mandatory and is one of the tests that the engineers are marked and graded on for SFI jobs.

@revk definitely thinks it isn't mandatory. His further implication is that it isn't even optional!

But that would mean if an engineer got to a job and couldn't get sync on his tester he'd walk off as long as the line is up to SIN349 standards! That's not what happens though.

The base module (for end users) of a SFI visit solely checks that the line is compliant with SIN349. This is a voice line test.

It's possible that the PSTN complies to SIN349, but the broadband service isn't in sync. The engineer would find out why the broadband service isn't in sync and that would determine who is responsible for the SFI charge.

Yep, have had an engineer do that. Despite an HG612 getting a connection sometimes at 6Mb on VDSL2 for 30s and then timing out, a JDSU on the same line could not get any kind of VDSL2 connection.

PPP session? And you did mean xDSL, not ADSL which worried me.

Edited by RobertoS (Tue 17-Jan-17 13:22:55)

In reply to a post by RobertoS:

PPP session? And you did mean xDSL, not ADSL which worried me.

Yes, ADSL or ADSL2+, VDSL2 faults wouldn't come out as an SFI job. PPP session-it just tries to connect to the BT Wholesale test server.

Edited by deleted (Tue 17-Jan-17 13:36:23)

But PPP? With where?

Edited by RobertoS (Tue 17-Jan-17 13:37:06)

I don't really understand your question! Maybe there's a different term for it but that's what we call it anyway. The tester basically checks that it can communicate with BT Wholesale's test domain. So it's checking that there's throughput basically.

In reply to a post by godsell4:

Yep, have had an engineer do that. Despite an HG612 getting a connection sometimes at 6Mb on VDSL2 for 30s and then timing out, a JDSU on the same line could not get any kind of VDSL2 connection.

Your visit wouldn't have been an SFI, they don't exist for FTTC jobs.

We're way off topic though here! This thread is about SNR for VDSL2 and somehow we're having a conversation about the merits of SFI!

Edited by deleted (Tue 17-Jan-17 14:01:23)

Yes but when an engineer goes out on an SFI job one of the tests they are required to do is an ADSL test on their handheld tester. This checks for errors and has a threshold, over which the test will be classed as a fail.

Except of course that the thresholds on the scripted tests are set very leniently indeed .......... It can even drop sync a few times and still deem it a pass ....... chocolate and teapot spring to mind.

You mention that these scripted tests check for a PPP session, nope, only the manual sync test (well on a JDSU at least) tests PPP, and then only to Btw test log in (this works on some LLU connections too)