Wednesday, February 20, 2008

Understanding MPLS VPNs

If you are an enterprise user of carrier WAN offerings, it is likely you've been offered MPLS as a solution. Most carriers are encouraging customers to consider MPLS based services over traditional Frame Relay, ATM and even Point-to-Point transport.

One misconception is that consumers of MPLS carrier services must "run MPLS" within their own networks or at least on the edge device(s) connected to the carrier's MPLS service. This is not the case (unless you are doing something pretty unusual). Standard routers -- and even bridges -- are used on the customer-side. The configurations may be a bit different than you're used to but they're still relatively straightforward (and cookie cutter once you do one).

Your layer 1 and layer 2 skills will still come in handy. The underlying transport is still going to be TDM (DS1, OC-3c, etc). You may end up running a dynamic routing protocol (BGP, OSPF) with the carrier's network. If that's new territory, don't worry. This BGP configuration is far less elaborate than that needed to (prudently) bring up BGP for Internet multi-homing.

So even though the MPLS component will be outsourced to your carrier, to be an informed buyer and troubleshooter when shit-hits-the-fan, you'll want to understand the different ways that MPLS can be delivered and used by carriers to provide your service. When the carrier asks you to make some choices or you're evaluating a prospective solution, you're more likely to get what you need (and hopefully less of what you don't).

Jeff Doyle, the author of Routing TCP/IP Volume I and II (both 900+ pages each), has two quick articles about MPLS. In Part I, he covers the basics relevant to any MPLS user as to the different types of MPLS network options and in Part II he covers some of the nitty gritty relevant to service providers and those with an interest in what goes on behind the scenes.

P.S. I have some experience with WANs. Feel free to ask me questions. You can post a comment here or drop me an e-mail.


Sunday, February 17, 2008

Improvements at Digium? ....and New AA50 Firmware

Yesterday I noted that Digium pushed out a new firmware release for their small business targeted hardware appliance (the AA50) and it looks like a good sized update. It is dated the 4th in the release notes but the 14th elsewhere so I think one or the other is a typo.

They appear to be syncing it up with their other code bases (Asterisk Business Edition, AsteriskNOW). From what I've seen in the public commits and hints on mailing lists from staff, they've been hitting pretty hard on both of those in the QA department of late.

Digium is clearly working on changing how they manage their code bases and the mixture of their commercial and open source releases, to address different customer/user segments and some of the problems that have come up. There was even a note about a split release change they are going to with AsteriskNOW for the GPL purists. Glad to see some serious re-thinking about releases, meeting the desires of different customers, quality control enhancements, and the public evidence of the aforementioned outside of press releases.

I imagine things will continue to trickle down and we'll see more improvements coming together. I'm sure some will turn out to be good ideas while others head back to the drawing board but that's how most progress works, eh? :)

The additional leverage should improve things across the board no matter where you fall in the Asterisk eco-system. Even if you don't use an Asterisk based telephony solution, their moves impact the others in the marketplace (and visa-versa).

Back to the new AA50 firmware release: It would appear to address IVR and ring group related bugs I encountering early on in the GUI, that I ended up bypassing the GUI to workaround. I haven't tried it yet on the AA50 I have access to. I'll probably give it another couple o' weeks in the wild first since it's a .0.1 rev. That client has some other problems and improvements they want me to attack first anyhow. Below are change log excerpts:

Version - February 4, 2008
* Enable Internationalization settings in the GUI
* Provide the ability to select between kewlstart and loopstart
* g722 codec is available
* WAN Side Provisioning of Polycom phones is enabled
* AA50 has been synchronized to ABE C.1 branch source code
* Ring groups number of seconds field has been added
* Ring group bug using ivr option has been fixed.
* Polycom bug concering use of standard timezone has been fixed
* Blackfin math for meetme conferencing has been implemented
* Adjustable flash hook duration is now available in teh GUI
* Calling rule editing and deleting bug has been fixed.
* Bug concerning setting incoming rule to choose voicemail is fixed.
* DTMF twist settings for Brazil have been added to tone generation
* Call forwarding loops have been prevented so that they do not crash the AA50
* Voicemail attachments are set to WAV format.
* Network setting tabs no longer disappear.
* Added an optional full-wave mode DAA ring detect in the sx00i driver

Friday, February 15, 2008

Starbucks Dumping T-Mobile for AT&T

I spend a lot of time at coffeehouses -- Starbucks and otherwise. This change ought to be handy (cheaper) for those of us with AT&T DSL at home already.

Supposedly will be implemented throughout the year and completed by year-end. We'll see.

Official AT&T press release

Professional Soccer Coming To SLO...In A Week

I just got done buying our tickets for the two weekend exhibition games being played by the San Jose Earthquakes. The nifty thing is that they are playing these games at Cal Poly, here in SLO. I'm really looking forward to it. I really enjoy soccer but I've never seen a pro team play in person.

They are set to play D.C. United and Columbus Crew. All three teams are in the American-based Major League Soccer, the top echelon of U.S. based professional teams. This league, incidentally, also has many non-American players in it including David Beckham who plays for the Los Angeles Galaxy (Galaxies?).

Official Cal Poly press releases here with more info on the event, tickets, etc.:

Cal Poly to Host a Pair of Major League Soccer Games as Part of the MLS Central Coast Showcase

San Jose Earthquakes to Train in San Luis Obispo the Week of the Major League Soccer Central Coast Showcase

Wednesday, February 6, 2008

Underwater Telecommunications Industry Geeks

For those who are interested in the inner workings -- both technical and business -- of the submarine fiber optic cable industry, take a look at SubOptic. Particularly recommended are the presentations from their last conference which are available to freely peruse all you like here.