Alcatel believes it has a way for service providers to introduce Ethernet data services without disrupting revenue they generate from frame relay.

The vendor this week unveiled software for its 7670 Routing Switch Platform -- a core multiservice Layer 2/Layer 3 switch -- designed to enable Ethernet VPN access to frame relay and ATM core networks. The software, called Service Interworking, maps frame relay data link connection identifiers (DLCI) to Ethernet virtual LAN ID tags.

Service Interworking eliminates the need for all corporate sites to be connected via Ethernet in order to communicate with each other, Alcatel says. Service providers would like to offer Ethernet services to their customers that have higher bandwidth requirements at many locations, but do not want the risk or costs associated with migration of the entire network to an all-Ethernet offering, the vendor says.

Ethernet services can be provisioned in 1M bit/sec increments, while frame relay circuits usually range from T-1 to fractional T-1 and 56K bit/sec. But frame relay is currently a cash cow for carriers, generating US$8.4 billion in U.S. service revenue last year, which is expected to grow to just under $11 billion by 2006, according to the Yankee Group.

But the belief among service providers that they'll have to migrate their frame relay infrastructures to Ethernet -- and disrupt that gravy train -- has limited widespread Ethernet service adoption, Alcatel claims.

"From a service provider perspective, I think there's a kind of a mentality that they have to re-architect their networks if they want to deliver Ethernet services," says Christin Flynn, director of carrier convergence infrastructure research at the Yankee Group. "That can be quite daunting."

By mapping frame relay DLCIs to Ethernet VLAN tags, Service Interworking creates a "unified" Ethernet/frame relay VPN, Alcatel says.

The software allows carriers to offer switched VPN services to their customers with the choice of mixing frame or cell relay with Ethernet access to the VPN. Service Interworking will allow enterprises and carriers to deploy the most appropriate access technology at each site, Alcatel says.

For example, a corporate head office could utilize high-speed Ethernet access at 200M bit/sec with the ability to grow in segments as small as 1M bit/sec, but its branch office frame relay access and customer premises equipment, which use lower-speed access rates, would remain unchanged.

All locations would continue to share a single VPN, Alcatel says.

There is standards work underway to define a common specification for frame relay-to-Ethernet interworking. But Alcatel -- which is the number-two vendor in multiservice WAN switches, according to Yankee Group, with installations at SBC Communications, Bell Canada, WorldCom and Broadwing -- decided to address its own customer interests first.

"We kind of got sick of waiting" for the standard to crystallize, says Vinay Rathore, director of strategic marketing for Alcatel. Rathore says it may be a year or two before the IETF, MPLS and Frame Relay Alliance, and ATM Forum agree on a standard, but "it's anybody's guess" as to when it will be completed, he says.

Nonetheless, Rathone says Alcatel's software will comply with the frame-to-Ethernet interworking standard when it is ready for implementation.

The Service Interworking software is available now free of charge for 7670 users with a maintenance contract.