In reply to a post by jchamier:

In reply to a post by David_W:

This 200 exchange deployment is focused on high speed (FTTx) and high margin (EFM and leased line) services. All the exchanges have FTTx available. The additional cost of Zen paying BT Openreach to provide an FTTx connection over Zen providing an ADSL2+ port on their MSAN and paying BT Openreach for SMPF is unlikely to be much, and will be more than cancelled out by the higher retail price for the FTTx service sold to the end user.

I think there are charges for each connection for SMPF, whereas for FTTC there is only the GEA links (multiples of) that need to be fitted. Potentially a one-off charge (maybe if using 10 GigE).

Having a GEA Etherlink (one-off charge of £2000 plus VAT per GigE) is all well and good - but it doesn't get an end-user connected. For that, you either need a BT Openreach FTTx connection, or BT Openreach SMPF/MPF and a ADSL2+ line card port.

My guess is that it isn't much cheaper for Zen to procure an ADSL2+ line card port and pay BT Openreach for SMPF or MPF than to pay BT Openreach for FTTx. I'd expect a business / enthusiast ISP like Zen to focus on FTTx where available, and their margins on FTTx are likely better than for ADSL2+. Moreover, the savings on BT Wholesale WBMC backhaul charges will be smaller for the (average) ADSL2+ customer than the (average) FTTx customer, because the faster FTTx connections are likely to be used more.


Only Zen know the economics of the various options. It's possible we will see LLU ADSL2+ from Zen using their new network, but I have my doubts. I think Zen are more likely to invest in enhancing the footprint of their network rather than in ADSL2+ line cards.

In reply to a post by jchamier:

In reply to a post by David_W:

Zen would also incur additional support and training costs if they launched SMPF and/or MPF services. It is debatable whether they could recover the costs of setting up the support infrastructure considering the relatively small proportion of exchanges with a Zen MSAN.

I was assuming all 200 Zen PoPs had an MSAN, unlike the 4 LLU exchanges which had old style DSLAM kit?

The ADSL2+ customers on 200 exchanges that all support FTTx will likely be relatively small proportion of Zen's overall ADSL2+ user base. How many exchanges are there in total?

See my edit to this post.

From what I've been reading, ADSL2+ on Zen's MPLS network seems not to be involved.

In reply to a post by RobertoS:

Why are you both calling the Zen exchange kit MSANs when Andrew has categorically said it isn't? I find that very confusing, even if in the absence of any other term you find it convenient .

Because, as Andrew said, it's a matter of definitions.

Zen call the kit they've installed MSANs, and that is an accurate description - it offers multiple services. It's quite likely that these MSANs could offer DSL ports with the appropriate line cards - but Zen has chosen not to offer LLU ADSL2+ using this kit.


The problem is with the overloading of the term MSAN. In the 20CN days, we got used to talking about DSLAMs. Come 21CN and LLU ADSL2+, we started calling about the exchange end of an ADSL/ADSL2/ADSL2+ circuit an MSAN, because the new generation of equipment used was capable of offering multiple services from one device.

As networks continue to evolve, we need to leave behind the notion that an MSAN in a phone exchange necessarily offers ADSL2+ ports.

In reply to a post by RobertoS:

Edit - looks like the kit is Label Edge Routers (LERs), linked to from the Wiki description of MPLS. The GEA link going straight to the LER.

The Zen kit may well be doing be more than a LER.

Zen offer various VoIP services, both to consumers and businesses. It's possible they're using these new network devices to connect their VoIP core to the legacy PSTN at some of the exchanges (which I guess is still done using SDH, after BT abandoned the 21CN voice concept).

It may be that Zen selected exchange hardware that gave them the option of fitting ADSL2+ and/or POTS line cards in the future if the economics of offering these services using SMPF/MPF is favourable.

It's possible Zen are providing EFM (one of the services they've announced using their new network) using multiple MPFs and EFM line cards in their MSAN rather than leasing a pricey EFM circuit from BT Openreach.


I'm sure there's someone here who can offer a better insight than I can as to the advantages and disadvantages of deploying modern MSANs in phone exchanges compared to other available hardware.

It's so that they can prioritise traffic properly on their network. Zen etc don't do QoS in this manner.

I'm sure there is a reason why punters would want to pay nigh on double what the Big Boys are doing unlimited and unshaped for, for a 200GB hard capped service.

I just can't think of it right now.

In reply to a post by partial:

for a 200GB hard capped service.

It's not hard capped. All that happens if you go over it is that you pay for the extra usage, there's no throttling or anything else applied to your line.

Ouch! So overrun to 250GB on the 200GB package is ninety five quid of your tax paid take home that month!

There's an RSS feed to tell you what your usage is to date, as well as the account portal, and if your trend shows signs of going over you get an email with the details.

So yes, if you're still stupid enough to go 50GB over your allowance then you pay for it (at £1/GB compared to Zen's £1.52/GB).

In reply to a post by Ignitionnet:

It's so that they can prioritise traffic properly on their network. Zen etc don't do QoS in this manner.

Ummm.

Zen may not hold a copy IP Profile, but:-

Class of Service

Traffic is managed across the network by assigning applications to traffic classes. Zen�s IP VPN solution offers six Classes of Service (CoS) with each having its own level of service priority and associated Service Level Agreement (SLA). Applications are
typically allocated as follows:

Class Service Priority and Applications

1 IP telephony
2 Video Conferencing / Media Streaming / Business Critical Applications
3 VoIP call signalling and Business Critical Application, e.g. Citrix
4 Business Critical Application, e.g. SAP
5 Business Critical Application / Bulk Data Transfer
6 Standard traffic, e.g. email / Internet traffic etc

Looks remarkably like PlusNet's classifications to me .