LLU / Unbundling

Forums › New Zealand Broadband › LLU / Unbundling

shaker111

6 posts

Wannabe Geek

#13378 7-May-2007 17:02

Hi there,
I am a bit of a novice when it comes to computer stuff.
I've been following the whole local loop thing in the news and had a question for interest's sake.

Basically, what is the difference (in laymans terms please!) between local loop unbundling and bitstream unbundling?

Thanks alot

grant_k

3539 posts

Uber Geek

Trusted

#69826 7-May-2007 17:13

Bitstream unbundling (aka UBS) is a LOGICAL unbundling if you like, where Telecom allow third parties access at Level 2 (I think) of the internet protocol. Basically, it is a low-level access which allows third party ISPs to do things like Throttle-on-cap, Traffic Management which may differ from Telecom's offerings.

UBS establishes a "Logical Tunnel" over Telecom's network from the customer to their chosen ISP.

LLU however, is an unbundling of the PHYSICAL COPPER WIRES i.e. separation of the customer's connection at their nearest exchange or roadside cabinet, at which point the signals are routed via third party-owned equipment such as DSLAMs etc, back to their chosen ISP.

LLU has obviously not been implemented yet, whereas UBS was implemented around 4 years ago.

At least, that's my understanding of the 2 options...

Now to all you pros reading this -- Barf, Fraktul, Juha et al -- how many marks out of 10 did I get?

Please feel free to correct any inaccuracies (I'm sure you will)...

shaker111

6 posts

Wannabe Geek

#69828 7-May-2007 17:17

Cool, so how do 3rd parties actually offer broadband via bitstream? Does it still have to go through the copper wires or is there some other way?

Cheers

grant_k

3539 posts

Uber Geek

Trusted

#69829 7-May-2007 17:29

It still has to go through the copper wires. Unless you have an alternate connection via wireless, Vector Fibre or TelstraClear cable (in Welly or parts of ChCh), you're stuck with Telecom's copper wires

UBS is a LOGICAL connection which means it still has to use Telecom's network to provide the PHYSICAL connection.

shaker111

6 posts

Wannabe Geek

#69831 7-May-2007 17:39

ok - this is starting to come together! Can you make the physical / logical distinction any clearer?

Thanks!

antoniosk

2358 posts

Uber Geek

ID Verified

Trusted

Lifetime subscriber

#69843 7-May-2007 19:48

shaker111: ok - this is starting to come together! Can you make the physical / logical distinction any clearer?

Thanks!

Copper lines are connected to a DSLAM - an aggregation point - which is then connected to a backhaul line connecting at an Exchange, which is then connected to an IP Switch or similar. The DSLAM speaks a certain language to your modem - ADSL is the acronym - and translates it for the switch.

In the past, ISP's could only take a wholesale version of Xtra's product, calculated on Retail less a % as margin. Telecom would connect all customer's to the Internet, and all traffic would go through Xtra's boxes - which was great for them as they could shoehorn heaps of users into the same equipment. Problem is that it is expensive to scale, and when it gets busy the whole service slows down.

UBS seperates the connection at the DSLAM from the switch mentioned above. Instead of all traffic being sent to XTRA for processing, all ISP's that use UBS are connected at key exchanges, and they do all the onward processing. This takes a load off Xtra (making that service run faster), and gives an ISP more control over the Internet side of life. All Telecom has to do is carry the traffic from the modem/dslam back to YOUR connection rather than theirs. The problem with this approach is that the backhaul, the line connecting the DSLAM to the Exchange, is typically old copper and limited in speed - a bit like saying the offramp to the motorway is really quick, but the motorway itself is congested. Not in all cases, but certainly enough if you read enough posts on this site.

LLU is the final step, where the connection to your premises is physically disconnected from Telecom and connected to the carrier of choice. In phase 1, only customers connected at Exchanges will be available - which is still a good deal of the country. At this point, the carrier can use their OWN DSLAM technology and their OWN BACKHAUL to provide an even more diffirentiated service. The line never goes near Telecom again except for basic maintenance. Problem with this approach is that it's expensive - a carrier now has to invest in connections and DSLAMs, and nobody is entirely sure about the state of each copper line (over 30 years, a lot of digging through those wires can happen). On average it should be better than now, it's just the scale of the difference.

And to make a cynical comment, all the 7 dwarves are going to fight it out over this copper, and while distracted Telecom will approach customers, connect them directly on Fibre and Mobile technologies (both unregulated), and offer a service you can't on copper.

________

Antoniosk

Bung

6487 posts

Uber Geek

Subscriber

#69856 7-May-2007 20:25

antoniosk:
Copper lines are connected to a DSLAM - an aggregation point - which is then connected to a backhaul line connecting at an Exchange, which is then connected to an IP Switch or similar. The DSLAM speaks a certain language to your modem - ADSL is the acronym - and translates it for the switch.

The problem with this approach is that the backhaul, the line connecting the DSLAM to the Exchange, is typically old copper and limited in speed - a bit like saying the offramp to the motorway is really quick, but the motorway itself is congested. Not in all cases, but certainly enough if you read enough posts on this site.

Are you trying to confuse the issue. How many remote DSLAMs connecting via old copper backhaul to exchanges would be out there?

grant_k

3539 posts

Uber Geek

Trusted

#69857 7-May-2007 20:34

Bung: How many remote DSLAMs connecting via old copper backhaul to exchanges would be out there?

Yeah, I was wondering about that too...

Most exchanges I've seen have one or microwave dishes on the roof. So I assumed the backhaul would be either DMR or Fibre?

Please correct me if that's not the case.

Cheers,
Grant.

Quic Broadband

Move to New Zealand's best fibre broadband service (affiliate link). Free setup code: R587125ERQ6VE. Note that to use Quic Broadband you must be comfortable with configuring your own router.

weblordpepe

460 posts

Ultimate Geek
Inactive user

#69985 8-May-2007 22:49

Copper copper everywhere!!

antoniosk

2358 posts

Uber Geek

ID Verified

Trusted

Lifetime subscriber

#69986 8-May-2007 22:54

Gents

It's a generic comment - i'm sure not all exchanges have just E1 feeds. But it's a fallacy to assume that just because there's a dish on an exchange, it's feeding the broadband network. There's lot of different services at an exchange!

There is more copper out there than people seem willing to accept, and Telecom is slowly adding fibre where it needs to. But there's more high value stuff out there than the heavily argued over broadband - and multiplexing multiple services together to go down a fibre line takes time money and effort....

________

Antoniosk

weblordpepe

460 posts

Ultimate Geek
Inactive user

#69992 8-May-2007 23:08

Thats right, and even if suddenly Telecom & all the ISP's were to go 'lets just blow all our cash & make the whole country have awesome internet' it would take a good while to forcast & plan everything, lettleown actually getting the techs out and installing stuff. Whatever the technology.

Fraktul

836 posts

Ultimate Geek

Trusted

#69997 9-May-2007 00:53

Pretty good Grant, UBS is layer 2 of the OSI model however, not IP. :)

In the past there were two wholesale ADSL services, FastIP and FastIP Direct. FastIP was a rate limited service better known at Jetstart and in this instance your ISP actually carried your Internet traffic directly. People seem to forget about Jetstart!

UBS allows a bit greater control of what you can choose to implement and pricing structure.

bondsms

2 posts

Wannabe Geek

#70037 9-May-2007 16:06

Can't you just make it ultra simple and say that wholesale is Telecom BB resold through another ISP, UBS is the ISPs Broadband using Telecom's DSLAM (the BB version of an exchange), and LLU is the ISPs Broadband using its own DSLAM, but still Telecom's copper wire to the premises.

and the suggestion that Telecom will roll-out fibre is pretty unlikely, the returns simply aren't there to justify that much investment, even if they beat the service of competitors. Plus the threat of regulation kind of makes this investment not worthwhile because as soon as they do it, they could be regulated since all their competitors will have stranded assets. it is possible to unbundle fibre too!. and that was the whole problem in Aussie is that the government wouldn't guarantee Telstra that it wouldn't unbundle its NGN, so Telstra refused to build an NGN.

Woolly

119 posts

Master Geek
Inactive user

#70401 11-May-2007 18:35

Just wondering

1. Is there Fiber to most City Telecom NZ exchanges?
2. How flooded is the backbone at the moment, where can I get the data?

Cheers