Domino's delivers hot and wild new net

ANN ARBOR, MICH. - For pizza deliveries, its tagline is "For Hot and Wild, Call Domino's." One could say the same about its network.

Domino's Pizza has installed a switched Layer 3 Gigabit Ethernet network to support existing and future enterprise resource planning (ERP) and multimedia applications and to guarantee quality of service (QoS) for voice-over-IP and other converged traffic.

The network is replacing a Layer 2 switched and shared 100M bit/sec Ethernet backbone, says Matt Maguire, Domino's director of IT.

"Going from Layer 2 to Layer 3 wasn't necessarily a technical reason," Maguire says. "If we were migrating, we might as well migrate to the latest technology."

The new network is a redundant campus backbone connecting redundant computer rooms and linking regional sites and distribution centers across the country to headquarters here over a frame relay WAN. The network supports PeopleSoft ERP applications for supply chain, human resource and financial operations; electronic commerce applications; intranet and extranet connectivity to franchisees; and Web-based tasks, such as market research.

The campus network is based on two Nortel Networks' Accelar 1200 Layer 3 backbone switches 1,800 feet apart connected via Gigabit Ethernet over fiber. The switches are replacing Nortel's System 5000 and BayStack 28115 Fast Ethernet switches and hubs in the backbone.

The Accelar switches take in multiple 100M bit/sec uplinks from BayStack 350 and 450 switches in wiring closets that connect Nortel System 5000 and Distributed 5000 hubs and switches to the backbone. Hanging off the Accelar switches are 65 Windows NT and NetWare servers housing the ERP and other applications.

Those servers serve up to 800 workstations at Domino's headquarters here.

Thirty-two remote sites - distribution centers and regional offices - are connected to headquarters over a frame relay network anchored by Nortel Access Node Hub routers. There are between 20 and 50 workstations, servers and other network nodes at each remote site, Maguire says.

While Maguire acknowledges some "upswing" in the performance of current applications by upgrading from shared media to switching, Domino's main objective with the new network is to accommodate future growth and save money. The company expects to shave $20,000 per month off of its WAN costs alone, Maguire says.

"What we're able to do is sustain our continued growth of new applications coming in, whether it's additional supply chain applications, or a treasury system, tax system or imaging system," Maguire says. "We're always adding things on, we're never taking things away."

The next major addition may be converged voice, data and video applications, Maguire says. Currently, Domino's Nortel Meridian PBX is supporting ISDN Primary Rate and Basic Rate Interface circuits to deliver videoconferencing to remote regional sites. Domino's plans to add Nortel's CallPilot software to the PBX to integrate e-mail and voice mail, and then plans to evaluate some Nortel voice-over-IP products for further voice/data integration, Maguire says.

Pretty ambitious plans, but Maguire says the company's new campus network can take whatever Domino's can throw at it - from a bandwidth perspective, anyway.

"We're pretty well-positioned to take advantage [of voice over IP] when product becomes available," Maguire says. The caveat is in reliability. Data networks have to be as reliable as - if not more reliable than - the current phone network for companies like Domino's to fully embrace voice over IP.

"[Data networks are] just not there yet," he says.

As for QoS, Domino's is currently just aggregating LAN bandwidth to guarantee response time for its ERP applications; there's no fancy queuing or traffic shaping going on.

For the WAN, though, where bandwidth is more limited, Domino's has to do some traffic policing. The company is using Packeteer's PacketShaper bandwidth manager to establish and enforce policies for prioritizing traffic and guaranteeing bandwidth across its frame relay network. PacketShapers apply TCP rate-based flow-control policies to both individual traffic flows and classes of flows to provide predictable service-level control for IP traffic.

TCP rate control is a traffic-shaping technique that paces or smoothes the IP flow by detecting a remote user's access speed, factoring in network latency and correlating this data with other traffic flow information. TCP rate control is designed to evenly distribute packet transmissions by controlling TCP acknowledgments to the sender, causing the sender to throttle back and avoiding packet loss when there is insufficient bandwidth.

This is in contrast to packet queuing in routers, which is susceptible to delay, dropped packets and retransmissions, resulting in a drop in network efficiency.

The PacketShapers also save Domino's money in that the company does not have to provision more frame relay permanent virtual circuits to ensure that all applications have access to bandwidth.

As an added dimension to QoS and bandwidth management, Domino's is taking a close, hard look at Nortel's policy-based networking initiatives. Nortel recently announced some Optivity management software specifically for defining, distributing and enforcing network service-level policies across its products (NW, May 31, page 15).

Policy will let Domino's make proactive network design decisions based on controlling what's going on within the network as far as allocating bandwidth based on traffic type, Maguire says.

"Policies are supposed to be able to police the network that you can't see so you don't get swamped," Maguire says.

In redesigning the network, Domino's maintained its commitment to Nortel. While the company did evaluate Cisco's Catalyst switches for the network overhaul, Domino's decided to stick with Nortel because Bay Networks was Domino's incumbent vendor, and the company was already quite familiar with the Bay product line. o