What's The DSLAM/MSAN In Cabinets?

I'm just curious as to what hardware is in the cabinets.

From what I can gather it's as follows:

96 port = Huawei MA5616 and 4 x 24 port VDSL2 line cards
128 port = ECI M41 and 4 x 32 port VDSL2 line cards
256 port = ECI M82 + 8 x 32 port VDSL2 line cards
288 port = Huawei MA5300 + 12 x 24 port VDSL2 line cards

This seem about right?

Obviously denser line cards than these do exist but to use them would cause BT some cable management headaches when they move to profile 30a as the current 30a line cards are only as dense as the ones mentioned here, they need twice as many DSPs as profile 17a, so to use the denser line cards would mean rearranging subscribers later on or having to wait for 30a cards to match that port density.

I dont know.

Sadly it seems on ECI for vectoring this is needed?

http://www.ecitele.com/OurOffering/Products/Pages/V4...

Can you ever see BT swapping out cards in cabinets? I cant. I hope the M41 is either software upgradeable or maybe an addon type card can be used.

Looks like the MA5616 can do vectoring so I am now wondering if BT's vectoring trials are HG only and we are going to see a split service with only HG users getting vectoring support.

Here V41 is mentioned.

http://forums.digitalspy.co.uk/showpost.php?p=646661...

Edited by Chrysalis (Tue 23-Apr-13 19:57:15)

According to Huawei, writing in its in-house magazine, the company's DSLAMs just need compliant CPE and a firmware upgrade (to V800R311, the first firmware revision to support g.vector.)

cheers, a

Is that enough to get vectoring beyond the simplest board-level? No need for backplane changes to get system-level or node-level vectoring?

when I was looking in one a couple of years back it had space for 6 * 48 line cards and six 1G fibre connections. Huawei.

Huawei MA5303 is a 6 line card chassis but any 48 port cards from a couple of years ago were I suspect profile 8a only so not found in the current chassis.

My Huawei 288 cabinet went live at the beginning of 2011 on 8a. Nothing was replaced on the move to 17a.

Pretty much what I thought in my original post, a 12 slot MR5300 loaded with 12 x 24 port VDSL2 cards.

There is only the briefest mention in the Huawei docs to hand, but from what I see, the backplane remains unchanged. It's a dumb component anyway in the MA56xx.

From the MA5616 Hardware Description - document reference V800R310C00 [1]:

"An MA5616 supports common and enhanced subracks. If an enhanced subrack is used, the
control board, service boards, and software versions of the MA5616 V800R311 can be used to
support the vectoring function."

I take it to mean that the "subrack" is the cabinet or rack enclosure that holds the MA5616 chassis. Huawei sells such a beast - "an enhanced subrack" although why a different rack should be needed for vectoring?!

Could well be wrong though.

It looks like it employs a system level vectoring architecture. Though back in 2009, Huawei was prototyping node level vectoring with two or more cascaded MA5616 chassis. [2]

cheers, a

[1] http://www.scribd.com/doc/126007087/Huawei-SmartAX-M...
[2] http://downloads.lightreading.com/wplib/huawei/Resea...

Edited by deleted (Wed 24-Apr-13 12:36:40)

The MA5616 is one of several MSANs (DSLAMs) that BT Openreach is installing in new fibre street cabinets across Britain, in perhaps the biggest telecoms revolution for a generation.

according to http://insidehuaweima5616msan.wordpress.com

There is a 48 port 17a board in the MA5616 range -
� 48-channel VDSL2 board (17a, over POTS, external SPL, supporting MELT)

also used in the pizza box variant perhaps http://www.huawei.com/us/products/fixed-access/dslam...

In reply to a post by yarwell:

The MA5616 is one of several MSANs (DSLAMs) that BT Openreach is installing in new fibre street cabinets across Britain, in perhaps the biggest telecoms revolution for a generation.

according to http://insidehuaweima5616msan.wordpress.com

There is a 48 port 17a board in the MA5616 range -
� 48-channel VDSL2 board (17a, over POTS, external SPL, supporting MELT)

also used in the pizza box variant perhaps http://www.huawei.com/us/products/fixed-access/dslam...

Yes, I know, did you read the last paragraph of my initial post?

In reply to a post by Ignitionnet:

Obviously denser line cards than these do exist but to use them would cause BT some cable management headaches when they move to profile 30a as the current 30a line cards are only as dense as the ones mentioned here, they need twice as many DSPs as profile 17a, so to use the denser line cards would mean rearranging subscribers later on or having to wait for 30a cards to match that port density.

yep, but having seen a 48 line card cabinet in the flesh I didn't take any notice

This one has 4 card capability with two fitted :
http://beusergroup.co.uk/technotes/images/e/ee/PICT8...

This one has 6 cards fitted :
http://superfastnorthamptonshire.files.wordpress.com...

may help with the confirmation

you have any idea which ECI used M41/V41?

What leads you to believe Openreach have any intention of moving to 30a? I got the impression that was ditched in favour of 17a vectoring, so long as that works as desired.

also ispreview are indicating vectoring wont be used to boost headline speeds either but rather for improving poorer lines, this has surprised me but I think thats a good thing to do.

M41

In reply to a post by asbokid:

There is only the briefest mention in the Huawei docs to hand, but from what I see, the backplane remains unchanged. It's a dumb component anyway in the MA56xx.

...

I take it to mean that the "subrack" is the cabinet or rack enclosure that holds the MA5616 chassis. Huawei sells such a beast - "an enhanced subrack" although why a different rack should be needed for vectoring?!

Thanks - I found the same hardware reference from that reference.

The subrack is indeed the steel box that the M5616 itself is mounted in, 19" x 3.5" (2U), and that all the linecards plug into. That kind of subrack is used to mount equipment in the 19" racks usually found in data-centres. Obviously our cabinets are cut & folded to provide the matching size of cutout, but vertically.

It is dumb, except for the backplane that the cards actually plug into - which help distribute comms and power between the various boards. Even the backplane might just be copper tracks on a PCB, or wires off sockets - but it is slightly less dumb than a steel box.

In some equipment, the external wiring goes to the backplane; in telco equipment the external wiring usually plugs into the front (as it does in our cabinets), leaving the backplane solely for wiring inter-board connections.

In this case it looks like the enhanced subrack contains an enhanced backplane, with additional communication channels between the boards - allowing the additional vectoring information to transfer between boards.

So it depends on the subracks that BT have ordered. If they're standard, there will be an outage while some hardware gets swapped in/out. It won't be a huge job, but it will be a site visit.

It looks like it employs a system level vectoring architecture. Though back in 2009, Huawei was prototyping node level vectoring with two or more cascaded MA5616 chassis. [2]

Excellent - that looks promising for a site with 2 Huawei cabinets then - we'll have to hope they don't mix vendor at different sites. It'd require some data transfer path between the 2 cabinets, presumably via the ducting.

[1] http://www.scribd.com/doc/126007087/Huawei-SmartAX-M...
[2] http://downloads.lightreading.com/wplib/huawei/Resea...

You always give excellent references. Much appreciated!

You're right,WWWombat!

Huawei seems to use the terms 'chassis' and 'subrack' interchangeably.

The company doesn't explicitly say it, but I suspect that vectoring functionality may require an upgrade to the latest controller board as well. Even so, it still wouldn't be as costly as the ECI upgrade for vectoring, currently requiring a whole new DSLAM.

cheers, a

In reply to a post by Ribble:

M41

then unless the M41 can support vectoring it doesnt bode well for those of us on ECI cabinets.

That's all cabinets in our area, they are all ECI

There's no mention of vector support in any documentation or on the website and I doubt ECI would bother doing anything to enable the M41 to support it, if it is indeed possible, when they have the V41 available.

I am not convinced BT are just using M41, they have in the openreach documentation vectoring compatibility is required so it was always in their heads of the chance of using it, and many ECI cabinets have been deployed very recently. It seems incredibly shortsighted to use cabinets that would require a hardware replacement to deploy something that was planned within 1-2 years.

Edited by Chrysalis (Thu 25-Apr-13 14:26:48)

Ahh I see, thank you Phil.

I see the 4 card one has 24 port line cards in it, the 6 port one clearly has 48 ports.

Thanks for correcting my assumption, and thanks all others for the comments about 30a not being on the Openreach roadmap, it's been informative.