Ethernet services

AlcaLu's Alwan: PBT Will Lose Its Shine

Controversial Ethernet technology Provider Backbone Transport (PBT) is benefiting from a wave of hype that won’t last, according to Basil Alwan, head of IP at Alcatel-Lucent (NYSE: ALU). (See PBT: New Kid on the Metro Block, PBT's Ethernet Appeal, and PBT Means What?)

That Alwan would say that comes as no surprise: AlcaLu is one of the major IP/MPLS router players that stands to lose out if PBT, also known as PBB-TE in the Institute of Electrical and Electronics Engineers Inc. (IEEE) standards process, picks up commercial momentum and is deployed in any scale by major operators. (See MPLS: Metro a No-Go?, Vendors Clash Over PBT, and PBT vs MPLS: Round VII.)

But while many views in the industry go unnoticed, the AlcaLu man is a respected and influential figure whose opinions carry weight in the vendor and carrier community. (See AlcaLu Expands Alwan's Role and AlcaLu Exec Wins Popularity Contest.)

Chatting to Light Reading on the phone after his recent presentation at the MPLS & Ethernet World Congress in Paris, Alwan admitted that PBT has attracted a lot of attention among major carriers, but he has his doubts that the technology will live up to the hype created by the technology’s supporters. (See PBT Key to Ciena Acquisition, BT Goes Live With PBT, BT Counters PBT Claims, Nortel Pushes PBT Pact, Nortel on PBT: Today BT, Tomorrow the World!, Nortel, Siemens Win PBT Deals at BT, Deutsche Telekom Flirts With PBT, and Huawei Joins PBT Fan Club.)

”The industry loves debate -- technologies go through a hype cycle and then settle into a role. The main thing about PBT at the moment is the provisioning and control plane functionality. It fits in with the traditional OSS that is designed for transport networks. The question for the industry is: Can we do these things in MPLS? Of course we can,” claims Alwan.

”The same market forces that drive MPLS will drive any carrier Ethernet product. It’s about plugging in with the OSS and carrier mindsets. That’s why we [Alcatel-Lucent] are agnostic."

Agnostic? Really? (See PBT Cost Claims Questioned.)

"PBT isn’t bad –- it’s an approach. But what problem is it solving?” asks Alwan.

”Some of the arguments [in favor of PBT] are short-term. They may be real today, but they don’t stand up in the long term. That’s my view based on 20 years of building switches.”

MPLS is 'hitting its stride'
Alwan recalls there were similar questions around MPLS when it was in the early stages of development. “When I first started working on this technology at TiMetra, we debated whether MPLS would become a mainstream technology. MPLS is just hitting its stride -- it went through its hype cycle, found its place, and now it has hit the market in a very major way, and has contributed to a renaissance in router design.

”Now there’s a huge amount of adoption by carriers such as Belgacom SA (Euronext: BELG), BT Group plc (NYSE: BT; London: BTA), Wind Telecomunicazioni SpA , and others." (See Wind Launches IPTV, Belgacom Uses Alcatel, and Alcatel Signs BT 21CN Deal.)

Repeat offenders
And just as this is happening, so another technology comes along, claiming to do many of the same things better and more cost-effectively. “This industry has the tendency to do the same thing but in different ways, and that adds complexity.”

Alwan adds that PBT has emerged as the telecom world is in flux. “We’re at a point where two worlds are colliding -- transport and packet Ethernet, and the carrier Ethernet debate has the headlines. But it’s not just about the technology. It’s about organizations, and politics within equipment companies and service providers.

“It’s an important debate, for sure, but we believe the way forward is to enhance MPLS. Hopefully [the industry] will take an MPLS approach to transport requirements. Let’s use the technology that’s already widely deployed. We have to stay focused on what our customers need.”

So won’t technology based on an eventual PBB-TE standard have a role to play at all? “I won’t comment on where PBB-TE might end up. There’s a lot of evaluation at the moment, and that’s good. But we believe that enhancing MPLS is the right direction. There’s a lot of overlap, and MPLS has a huge headstart.”

What does PBT 'bring to the party?'
Alwan is clearly irritated by the way some of the PBT debates are evolving, particularly around relative cost and functionality. PBT’s supporters stress how its functionality is based around “MAC address encapsulation -- but what does that bring to the party? That’s the big question on the table... If you go the chip level there is zero difference between the address lookup in MPLS addresses compared with MAC addresses. The big difference in cost at the moment is linked to scale. I don’t expect a cost differential to exist [in the future] -- there is no fundamental basis for it.”

He continues: “2008 is going to be a pivotal year in this particular debate, and the goal should be to enhance MPLS to further support OA&M [operations, administration, and maintenance]. MPLS has real contracts, real networks –- there are hundreds of networks being built based on that technology.”

MPLS set to improve
MPLS is going to improve, Alwan believes. “Network performance monitoring and performance management -- TDM networks have this, but MPLS still has to bake this in and have a standardized approach. Part of the tension around the transport-versus-packet debate is around this area. That’s a debate that will be resolved in time,” says the AlcaLu man.

In the meantime, Alwan is bullish about the future of Ethernet as a carrier-class service technology. “2008 will be a big year for carrier Ethernet. Ethernet as a service -- that’s what is really going well right now. It’s a really strong market.” (See Ethernet Services Hit $9.4B.)

— Ray Le Maistre, International News Editor, Light Reading

Page 1 / 4   >   >>
delphi 12/5/2012 | 3:47:16 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine MPLS and it derivatives are still too complex and operationally expensive for Layer 2 switching and transport. I think we have seen how well Alcatel has been managing future products. MPLS and Carrier Ethernet are not compatible. A lack of products in a market segment does not constitute a strategy.
gbennett 12/5/2012 | 3:47:16 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine Hi delphi,
I agree that MPLS has gathered an awful lot of moss since was positioned as "ATM without the complexity".

But is the best solution to:

A: Put MPLS on a diet. Take the parts you really want, and that help solve the problem you face - in this case for a simple, Ethernet & IP-friendly transport system that supports both dedicated capacity and stat muxing.

B: Invent something totally new and incompatible.

Option B always looks more attractive when you feel that any established technology is getting old and flabby (essentially it's the "grass is greener" viewpoint). But all that happens is that the "skinny new" solution you replace it with eventually ends up being loaded down with "enhancements". That's exactly how MPLS got where it is today.

I'm not going to harp on about the pros and cons of PBT vs T-MPLS, but as a general principle it makes sense to me to back a winning technology. Let's invest in making sure MPLS is fit for purpose - whatever the application.

I don't think there's anything fundamentally wrong with MPLS as a hierarchical labelling scheme. It's all the other baggage it has to carry with it that has to be rationalised. Some we keep, some we throw away.


davallan 12/5/2012 | 3:47:14 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine Geoff:

Problem with option A is you are reducing the addressable market of **your** product...somthing not likely to happen....

As for choosing and pruning, it is not endemic to the culture where MPLS originated, which it why we get typically two ways of doing things...let alone deprecating parts of one...

Option B the industry has no real stomach for IMO if you are truly referring to starting from scratch.

And I'm not sure Ethernet fits in the class of "starting from scratch". IEEE has done a pretty good job of keeping the moss off Ethernet for 30 years while progressively enhancing it. I do not believe they are about to change now....


delphi 12/5/2012 | 3:47:13 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine Geoff,

I think that PBT (and derivatives) are not inventing a new technology. It is taking an existing technology which is more fit for purpose than MPLS for Layer 2 management. MPLS is way too complex and fat and was created for Layer 3 and above management in a multi-protocol world. If all you want to do is switch and transport pre tagged bits across a flexible optical network why would you pick MPLS or its derivatives?
Belzebutt 12/5/2012 | 3:47:12 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine It's funny how the same companies that had been harping about the ATM tax are now asking customers to run a half-dozen different headers one on top of the other.

Anyone who sees the PBT stack immediately gets a blast from the past, it's like what POS did for optical router links vs. ATM.
light_read 12/5/2012 | 3:47:11 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine Most of the services today in internet are IP based and NOT layer-2 based which require IP enablement at somewhere to communicate to the Internet world.

So the real question is how far you may extend the layer-2 domain?

gbennett 12/5/2012 | 3:47:05 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine Hi delphi,

We may have to agree to disagree about MPLS being more or less "fit for purpose" than PBT :-)

I think you need to separate three distinct aspects of these architectures:

- The labelling (and therefore switching) aspects (present in both MPLS and PBT)
- The Control Plane (absent in PBT)
- The applications (many and varied for MPLS, only one for PBT)

Let me explain what I mean by these...

MPLS offers a simple, hierarchical encapsulation scheme that is not tied to either Layer 2 or Layer 3. For instance, it can be used very successfully with other "MAC Layers", and it could theoretically have been used with other Layer 3 protocols. I suppose the only Layer 3 example of importance today would be IPv6. I think this simple, and easily scalable labelling scheme is genuinely "fit for purpose", so what's not to like?

Control Plane
MPLS began life with a simple Control Plane. I won't get bogged down in discussing this in detail, but suffice to say that since then it grew without any overall idea of what we'd be using MPLS for. (This is not meant as a criticism of the people involved G itGs pretty tough to predict the future!!). So I think it's perfectly reasonable to take a step back today and discuss how to rationalise it with the benefit of hindsight. This would actually be a very useful exercise if we could do it without too much vendor-specific campaigning. I think Dave made a good point in Post #3 on this.

MPLS began life as an IP-friendly alternative to ATM. Since then it has been adapted for a wide range of other applications, such as Layer 2 and Layer 3 VPNs, and extending it into the SDH/DWDM layer as a transmission network control plane.

WhatGs the problem?
ThereGs too much GǣprotocolGǥ in the MPLS stack. And the uncoordinated growth of protocol has been triggered by the need to use MPLS for new applications.

I think in isolation you could argue that MPLS has been extremely successful as a technology for Layer 3 VPNs. And in isolation you could make the same argument for MPLS as a Layer 2 VPN technology. You can carry on with such arguments for each of the application areas for which MPLS has been used over the years.

Now we have an interesting application challenge for MPLS as a low cost, simple, Gǣcircuit-switchedGǥ transmission architecture for the delivery of Ethernet services. For this application itGs clear that the mass of protocol that we now see as GǣMPLSGǥ is too flabby. In my personal opinion I think the labelling scheme is fine, but IGm open to discussion on that.

But the rest of MPLS G the Control Plane and associated GǣprotocolGǥ that goes with it is pretty bulky. The argument goes that itGs hard to implement a cheap Ethernet switch that uses MPLS. Similarly the argument goes that itGs hard to manage MPLS because of all the associated protocols. At the moment IGm not personally convinced by these arguments, but I could be swayed. I think the issues are being distorted by vendor agendas on both sides (no change there then!)

So the conclusion that is being presented is that MPLS is a poor choice for the delivery of low cost, simple-to-manage Ethernet services G so letGs turn the clock back to 1995 (which is when the first stirrings of MPLS began) and write something new.

I challenge that conclusion because thereGs nothing intrinsically wrong with the basic labelling scheme of MPLS. So if the problem lies in the protocol and Control Plane G letGs fix that.

I also predict that if PBT carries on, that very soon we'll be talking about adding both control plane and application protocols to this "simple solution", and in three years we'll have something as bloated as MPLS is today.

Sorry to ramble :-)

Munster 12/5/2012 | 3:47:04 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine Hi

Isn't the simplified, transport-centric MPLS that Alwan is looking for T-MPLS (i.e. Transport MPLS as standardised by ITU-T and not MPLS-TE)?
That operates in an identical fashion to PBT, but is based on MPLS as a starting point rather than PBB.
Contrary to many statements made about T-MPLS, it is actually standardised by ITU-T already - just lacking work on ring topologies. It doesn't have a control plane either right now, but being based on MPLS, it's a case of "take your pick"!

When you look at PBT and T-MPLS, which are both addressing a pure "get the bits from here to there" problem, it seems many people are missing the plot. Perhaps the need is just for a reliable transport, like SONET/SDH and that IP/MPLS remains doing what it does well - delivery layer 3 services.
digits 12/5/2012 | 3:47:04 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine Very interesting and informative posts - thanks to everyone who has contributed.

There seems to be a growing consensus that tallies with Basil Alwan's view -- that once PBB-TE is fully-formed it may well have many of the attributes that, according to testimony, can make MPLS challenging to deploy.

I have heard some industry folk refer to PBT as the 'Emperor's New Clothes' -- 2008 might help us decide whether this is anti-PBT spin or more an accurate assessment.

douaibei 12/5/2012 | 3:47:04 PM
re: AlcaLu's Alwan: PBT Will Lose Its Shine Very good point:
I do believe in technology that PBT has no difference to MPLS in the end even if there still a gap between two at present.

PBT and MPLS was just a technology to provide the service, MPLS is quite mature to provide almost any service, but PBT which originally proposed to replace the SDH still falling far behind.

Commercially the chipset of both technology will become same or a dual mode chipset will be available .

PBT is evolving to the PBB-TE which introduced the control plane, are they any difference ?

still the control plane will be complated like MPLS, there is no way to simplify the network complexity while provide the same automatic mechanism as MPLS.

the realistic to carrier is stick to mpls as much as possible and take a eye on the PBT.

at present, only mpls can provide all the service that is critical to carrier not the PBT.

Page 1 / 4   >   >>
Sign In