x
Optical/IP

MPLS: King for a Day?

Some fundamental questions concerning the future of Multiprotocol Label Switching (MPLS) in large-scale telecom networks are being raised by a project in Germany run by Siemens AG (NYSE: SI; Frankfurt: SIE) and a bunch of technical institutes and universities.

The project, called “KING” after the German for “components for next-generation Internet,” aims to demonstrate that connectionless protocols like Internet Protocol (IP) offer the best chance of giving carriers the three things they really care about on very large networks: control over quality of service, control over network reliability, and automation of network management.

The implication of this project is that MPLS can't cut it on these issues because it relies on setting up virtual connections across networks -- in the same way as frame relay and Asynchronous Transfer Mode (ATM) do. As the number of virtual connections increases, the task of keeping control of everything gets tougher and tougher.

MPLS "is something like ATM in a different color," says Karl Schrodis, head of technical planning for the KING project.

The difference between connection-oriented and connectionless protocols is similar to the difference between rail and road transport. Railway companies have to keep a close eye on where trains are to avoid collisions on their connection-oriented tracks, and doing that gets increasingly hairy the more tracks and trains they have [ed. note: especially if your trains are in the U.K. and being run on rails overseen by Railtrack].

In contrast, no central control is needed for folk driving automobiles. They may set out with a particular route in mind but can choose to divert around any congestion they encounter at almost any junction.

The key point is that connection-oriented protocols avoid congestion while connectionless ones find a way around congestion, if and when it happens.

This means that connectionless protocols make better use of infrastructure when handling volatile Internet traffic. They're also potentially much more scaleable because there's only a general need to make sure there's enough overall network capacity to carry the traffic. As a result, they're easier to manage and their resilience increases with size, because there are more options for avoiding congestion.

All of this has been proven on the Internet, based on the connectionless IP, which has scaled so well and amazed everybody by its resilience.

Originally, MPLS was invented to speed up packet forwarding in IP backbones, according to Schrodis. However, advances in hardware technology by companies like Juniper Networks Inc. (Nasdaq: JNPR) have rendered this unnecessary. "The reason for having MPLS has gone," he says.

"We don't want to say MPLS is generally bad," Schrodis hedges, probably because it would be politically inept. Siemens, like plenty of other vendors, has climbed on the MPLS marketing bandwagon.

Schrodis and his colleagues in the KING project are aiming to add some bells and whistles to existing connectionless IP protocols to improve their performance. The multimillion-Euro project started last October and is scheduled to continue for three years. This will include "some sort of field trial at some point in time," says Schrodis.

Three fundamental additions to IP are being considered in the KING project.

The first ensures that every node in the network can provide at least two alternate routes for outgoing traffic. It also provides a balancing mechanism so that outgoing traffic can be split among multiple ports.

The second establishes a mechanism for controlling quality of service that balances traffic load and network capacity in a more general way than the admission control that's applied to individual links in ATM networks.

The third development introduces mechanisms for dealing automatically with common network problems. This aims to improve resilience while minimizing the need for manual intervention by a carrier's operations staff.

Right now, Schrodis is reluctant to divulge further details of what could end up being an MPLS killer. Time will tell whether the concept will go the way of SMDS (switched multimegabit digital service), a project that also trumpeted the advantages of connectionless protocols but never gained serious traction.

Still, the folk backing the KING project deserve to be taken seriously. In addition to Siemens, they include famous technical academic institutions such as the Fraunhofer Institute as well as universities in Essen, Karlsruhe, Munich, Stuttgart, and Würzburg.

Siemens et al aren't the only ones looking to retrofit IP with new capabilities. Dr Lawrence Roberts, one of the Internet pioneers, is also said to be working on similar schemes at his latest venture: Caspian Networks (see Dr. Lawrence Roberts and Caspian Study: The Internet's Exploding).

— Peter Heywood, Founding Editor, Light Reading
http://www.lightreading.com Want to know more? The big cheeses of the optical networking industry will be discussing this very topic at Opticon 2002, Light Reading’s annual conference, being held in San Jose, California, August 19-22. Check it out at Opticon 2002.

Register now and save $500 off the registration fee. Just use the VIP Code C2PT1LHT on your registration form, and deduct $500 from the published conference fee. It's that simple!

Page 1 / 7   >   >>
mplsrocks 12/4/2012 | 9:57:55 PM
re: MPLS: King for a Day? A number of companies including Siemens are leading high profile efforts into trying to develop a technology which provides the best of both worlds - QoS guarantees and scalability of connectionless protocols.

A research project spun out of Indian Institute of Technology, Bombay, India, claims to already have retrofitted MPLS to enable a connectionless scalable network providing QoS guarantees. The company is named eInfinitus Technologies, and the technolgy, xMPLS, is a software module which goes into the router OS and uses existing standards including LDP and SPF.

Check out http://www.einfinitus.com/pape...

Have these guys actually solved the holy grail of networking...

mplsrocks
fgoldstein 12/4/2012 | 9:57:54 PM
re: MPLS: King for a Day? Rather by definition, connectionless (CL) networks are memoryless -- each packet is carried without context. So parameters like "bits per second" and "delay variation" are unmanageable, because they require memory. This is not a problem for web browsing, FTP, mail, or other typical Internet data applications, because they don't have millisecond-level time criticality or, for that matter, visibility. That's why the Internet caught on, and why IP worked so much better than, say, X.25, which carried the connection-oriented (CO) paradigm to extremes.

But connectionless was, it turns out, a mistake. X.25 was a bad example of CO but the dominant one. ATM and Frame Relay are both lightweight connections, simple and fast. MPLS is what happened when the IETF realized that ATM and FR were good but invented elsewhere, so they came up with a new name and some syntactic sugar of their own.

If all you want to do is browse the web or upload the latest MP3s or even heavily-buffered MPEG-4 streams, CL is fine. But if you want to do real telephony (where every millisecond counts) or other time-critical apps, then CL can't hack it alone. KING sounds like one more attempt to use brute force around the problem.

Of course in the early '80s, many Europeans, I think Siemens included, were just as adamant in support of X.25, when it was the local orthodoxy. Converts tend to be the most fanatical of the true believers.
strands555 12/4/2012 | 9:57:53 PM
re: MPLS: King for a Day? rjm answering fgoldstein:

But connectionless was, it turns out, a mistake.
____________

How can anybody say this while posting messages on a web site, a web site that wouldn't exist if it weren't for a connectionless network?
===========

Because that somebody is--in his own words from post#2--a fanatical convert. But he apparently can't see that for some reason.
rjmcmahon 12/4/2012 | 9:57:53 PM
re: MPLS: King for a Day? But connectionless was, it turns out, a mistake.
____________

How can anybody say this while posting messages on a web site, a web site that wouldn't exist if it weren't for a connectionless network?

If my memory serves studies reveal that 63% of the US population, if given one choice for a network, would choose the webs and the connectionless internet over phone, cable, etc.

Our mistake has been expecting over priced "connection-oriented" monopolies and conflicted federal representatives to enable the bandwidth abundance our society deserves.
Holy Grail 12/4/2012 | 9:57:52 PM
re: MPLS: King for a Day?
Come on LightReading, not another round of "is MPLS BS?" The cynics amongst us are starting to think that whenever your short of real news, you decide to play the game of "let's throw a Hand Grenade at the MPLS folks and stand back to see what happens!"

The analogies are poor at best, but let's try to work with them. Is anyone broadly familier with experience of being in a traffic jam, like when driving through London or on the M25? If so then welcome to the world of connectionless networking.

Yes I have a car, but sometimes I take the train, especially when I need to arrive on time.

Now some people say that the answer is to build more roads, but then studies show that if you build more roads, then you get more people driving on them and this makes congestion worse, not better.

The answer is that MPLS adds some connection oriented features into the connectionless model.
Just as I choose to use the train from time to time, some network architects may choose to use MPLS from time to time. It is always nice to have the option, to abandon IP in favour of ATM would be to throw the baby out with the bathwater.

Siemens - Don't make Washing Machines or Fridges or something?

Anyone want to throw a few million Euro's my way?

Point of information, in the UK Railtrack as the name rather suggests, is responsible for the "Rail Track" and not for running the trains as stated in the article.

Running the trains is the responsibility of, yes you guessed - "The train operating companies", of which there are several.

Holy Grail
netskeptic 12/4/2012 | 9:57:52 PM
re: MPLS: King for a Day? > In contrast, no central control is needed for
> folk driving automobiles. They may set out with
> a particular route in mind but can choose to
> divert around any congestion they encounter at
> almost any junction.
>
> The key point is that connection-oriented
> protocols avoid congestion while connectionless
> ones find a way around congestion, if and when
> it happens.

Oh, yeah, it was just yesterday I was driving home from a short vacation and got into a traffic jam 15 miles away from the exit I had to get out. I suppose these guys do not drive cars often enough to use car analogy.

Yes, CL can provide reasonable QoS (simple packet coloring will do it) as long as there is enough spare bandwidth (a-la-Ethernet), otherwise it all comes back down to reserving circuits. It does not mean that MPLS makes much sense, though.

Thanks,

Netskeptic


geof hollingsworth 12/4/2012 | 9:57:51 PM
re: MPLS: King for a Day? In contrast, no central control is needed for
folk driving automobiles. They may set out with
a particular route in mind but can choose to divert around any congestion they encounter at
almost any junction


Wouldn't a more accurate auto traffic analogy be to note that if they encounter congestion which can't be diverted around, they (and the rest of the cars near them) are shunted onto a side road and forced to return to their original point of origon to start the jouney afresh?
Steve Saunders 12/4/2012 | 9:57:51 PM
re: MPLS: King for a Day? "The cynics amongst us are starting to think that whenever your short of real news, you decide to play the game of "let's throw a Hand Grenade at the MPLS folks and stand back to see what happens!"

You caught us!

p.s. thanks for the Railtrack correction. fixed now.
strands555 12/4/2012 | 9:57:50 PM
re: MPLS: King for a Day? Let's not give our highway departments any ideas. They may start posting "congestion police" at each freeway overpass with laser vaporizing guns to periodically "drop packets" from the freeway. "Hey, it works for the network guys" they'd say.

Hmmm...on second thought, maybe not such a bad idea. Start with the old beaters spewing pollution, then vaporize any vehicle where the driver is talking on a cell phone. That would reduce traffic by 50%. Because of that permanent traffic reduction, fewer freeways would need to be built and the funds could be diverted to building fiber-to-the-home. Yeah, that's the ticket.
skeptic 12/4/2012 | 9:57:50 PM
re: MPLS: King for a Day? ATM and Frame Relay are both lightweight connections, simple and fast. MPLS is what happened when the IETF realized that ATM and FR were good but invented elsewhere, so they came up with a new name and some syntactic sugar of their own.
=================
MPLS was what happened when several people
started to see the advantages of a generic
standards based encapsulation technology that
wasn't tied to hardware.

MPLS is a whole lot more flexable than anything
in FR or ATM. And whatever faults the IETF had,
they didn't produce "overkill" standards like
the ATM forum did.
Page 1 / 7   >   >>
HOME
Sign In
SEARCH
CLOSE
MORE
CLOSE