You've successfully layered ATM on top of an OC-48 fiber backbone in metropolitan New York, migrated dozens of mission-critical servers from Manhattan headquarters to a New Jersey data center, and dropped in switches that enable you to build virtual LANs between the two sites. So what do you do for an encore?
If you're Bear, Stearns & Co., Inc.'s CTG unit, a cowinner of Network World's 1996 User Excellence Award, you make it bigger.
Consider the steps Bear, Stearns has undertaken in recent months. The company is planning to nail up a second OC-48 fiber ring in the metropolitan New York area, linking company headquarters on Park Avenue to a Whippany, N.J. data center and to a backup trading floor operation in Brooklyn. The ring employs 2:1 wave division compression from switch supplier Northern Telecom, Inc. and soon will move to 8:1 compression, according to Ken Starkey, a managing director in the Communications Technology Group (CTG) unit. And, by next June, the financial giant will string up two additional OC-48 loops with the ability to add four more down the road.
Why all the bandwidth? Bear, Stearns needs it to support the growing legions of servers now being centralized in the Whippany data center. When we last visited with the company a year ago, engineers had relocated some 60 servers from Park Avenue. Now almost 200 servers call Whippany home.
Client workstations in Manhattan communicate over the ATM/Synchronous Optical Network (SONET) net to access data, each session managed by either Lucent Technologies, Inc. ATMizer or Bay Networks, Inc. C100 LAN switches. The switches support VLANs, making it possible to provide local workstation users with near real-time response, and still, in the event of a circuit or a switch outage, allow sessions to bounce back within 15 seconds.
Don Henderson, a managing director in the CTG unit, says the group has been busy during the past year dropping in additional VLAN switches to support more of these workstation-to-server connections between Manhattan and New Jersey.
Moreover, Bear, Stearns is evaluating Gigabit Ethernet and Multi-Protocol over ATM (MPOA) switches to provide 100M bit/sec bandwidth to local workgroup users, Henderson says.
"Like everyone else, we're hedging our bets between Gigabit Ethernet and MPOA," Henderson says. The goal, ultimately, is to boost performance - desktop users will communicate at 100M bit/sec, and servers will link over gigabit connections. The switched network upgrade came during a major facelift that also introduced NT Servers and new desktop systems to branch sites.
In addition to working in emerging technologies such as Gigabit Ethernet or MPOA, CTG engineers have managed to take the same model they used for VLANs in the New York metro area and deploy it to about 10 offices domestically. Basically, CTG converted the sites to a switched network architecture, Henderson says.
With the switched architecture in place on the domestic front, Bear, Stearns plans to turn its attention to international sites such as Hong Kong, Tokyo and London in the next few months.
With all they've been through over the past year, Starkey and Henderson say CTG has learned valuable lessons. For instance, they say careful analysis and testing of VLAN designs is essential to the implementation process.
"In a routed environment it was easy to deal with scaling," Henderson says. "With VLANs, you have to understand the traffic loads, node counts and people counts, and the impact they have on network performance."
Sums up Starkey: "You have to learn a lot more about your data flows and applications to provide the quality of service you need."
