So, OK, what else?
First, let's cover what we have so far. The telecom infrastructure convergence stew, regardless of who brews it, will have a few recognizable chunks of technology: MPLS, Ethernet, IP, and optical transport. What we don't necessarily know yet is where operators will converge first: access, metro, or core.
The easy answer is "it depends." Carriers are already converging in the core of their networks, using "Martini Draft" VPNs to carry Ethernet, Frame Relay, and ATM connections over their MPLS cores, while a few daring CLECs are converging their metro networks using pure-play Ethernet solutions capable of carrying just about any service, even TDM, over an Ethernet-based transport layer.
Last week at the Light Reading Live event held in both Washington D.C. and New York, "Carrier-Class Ethernet," the nod went to access, at least from the IXCs. Keynote speakers from MCI Inc. (Nasdaq: MCIP) and AT&T Corp. (NYSE: T) referred to their offerings with the same term: converged packet access (or, since nothing serious can be said in telecom unless wrapped in an acronym, CPA). CPA is in many ways more daring than any convergence effort to date, as it extends the carrier's packet-switched network (PSN) all the way to the customer's premises. Why do IXCs like this concept so much? And how can they justify the capital spending (capex) to roll out CPA network wide? The arguments for CPA can be boiled down to three:
Why pick Ethernet? With Ethernet, a gigabit-speed connection can be carved up into high- and low-grade service channels with statistical multiplexing and link-level operations, administration, and management (OAM). In short, Ethernet is becoming carrier class, and that means it can become the universal connection jack through which customers connect to all their communications services.
AT&T's Richard Klapman, group manager of Ethernet and INCS, put it best: "What is a softswitch but an Ethernet switch with voice applications running on it?" In that light, would you want access over anything other than Ethernet?
So how do we get there from here? MCI's Jackson dove into technical details, describing the need for four network elements. Here they are:
1) The building aggregator, or a little "pizza box" that aggregates customer traffic into Ethernet, then maps that into GFP or X.86 connection depending on the uplink (aggregation is likely to be VLAN-based today, but will evolve to MPLS-based pseudowires in the future);
2) A multiprotocol crossconnect, located in the MCI point of presence, which comes with integrated TDM and packet switching, for multiservice grooming and handoff to the interoffice facilities, or metro rings;
3) An optical add-drop multiplexer for scaleable IOF transport;
4) A service network edge router, loaded with Gigabit-Ethernet interfaces, MPLS capabilities, interworking functions, and all the other packet-based tools necessary to facilitate convergence.
The goal of this architecture is to get to packet-based services as early as possible. Once packetized ("inside the cloud," so to speak), traffic has been decoupled from physical facilities. This is something that Gady Rosenfeld of Corrigent Systems Inc. has been driving home. It's a critical point to understand when discussing the values of Ethernet, MPLS, and converged access.
AT&T's Klapman says the industry needs to provide 100 percent access, and that means making Ethernet-access solutions cheap enough to deploy everywhere, not just for Fortune 500 companies. It also means that carriers need to cooperate to achieve the same level of interoperability with Ethernet that they have with their TDM networks. He also says the industry needs to solve VLAN complexity. Though Ethernet gear has come a long way towards achieving the stamp of "carrier class" there remain considerable challenges in implementing carrier-Ethernet security, multi-vendor QOS, scale, OAM service features, and economics.
Regardless, it's now clear from the presentations at our recent live events that the universal move to Ethernet is finally happening, at least in the IXC world. In the world of CPA, the operator is looking for a way to say, "I will hand you an Ethernet interface and connect you to any service you agree to pay for."
At least that's what I thought, until someone took me aside during a break and said, "They can't really afford to do this, can they?"
I grabbed a croissant and said, "We've got a conference for that, too. Come see us in December."
(Light Reading's Telecom Investment Conference is happening in New York on December 15. Stay tuned for details.)
— Scott Clavenna, Chief Analyst, Heavy Reading