Hospital's ATM WAN untangles T-1 snarl, reduces costs

Chicago

T-1 lines at Rush Presbyterian/St. Luke's Medical Center were piling up so fast that the wiring closet was starting to look like a snake pit.

With hospital medical offices moving to new buildings and more private practices tapping into hospital network resources, the medical center was ordering a new T-1 every two weeks, according to Prasad Ravi, director of telecommunications at Rush Presbyterian/St. Luke's.

By purchasing a remote access switch from Sentient Networks and bargaining shrewdly with phone companies, Ravi got rid of the cable snarl by consolidating the T-1s onto T-3 pipes.

He invested $39,000 in a Sentient Ultimate 1200 WAN access switch that can handle two T-3s - the equivalent of 56 T-1s - leaving the hospital with room to grow. The price was about half the cost of the other alternatives he considered.

The hospital runs ATM over 40 T-1s to private medical groups and hospital buildings. The T-1s were terminating on FORE ASX 1000 switches in the hospital data center.

Terminating all the lines on the FORE switches was expensive; six-port T-1 cards cost $12,000 each. The cards ate up so many switch slots that the hospital was going to have to buy more switch chassis at a cost of $35,000 to $40,000 each, Ravi says.

"Every slot taken up by a T-1 card is a slot we could have used internally for the LAN," Ravi says. "It's much better to use those ports for OC-3 pipes than for T-1 pipes because you are wasting the ATM switching capacity of the chassis."

Ameritech suggested aggregating all the T-1s onto T-3 lines, and Ravi cut a deal to pay only for the bandwidth actually used on the T-3s. The hospital pays a flat fee per T-1 that is less than the $600 tariffed rate for a long-range T-1 service. The flat fee is also better than the $220 minimum it would cost for a very short T-1, Ravi says. Part of the deal with Ameritech requires that Ravi not reveal the exact price of the flat fee.

Ravi managed to negotiate the agreement with Ameritech because he played Ameritech against Avenew, a competitive carrier that had been providing the hospital with T-1 lines.

Ameritech suggested terminating the T-3 lines on a Cisco router already owned by the hospital. But that would have cost about $47,000 for a DS-3 router card that didn't support ATM. Ravi rejected the proposal.

Ameritech then suggested that the medical center buy a Telco Systems multiplexer that would take in one T-3, demultiplex the traffic into 28 T-1s, and plug the T-1s into the FORE ATM switches.

That proposal would have cost $85,000, and still would have mandated wasting valuable ATM switch fabric by using the T-1 cards. Ravi rejected that proposal, too.

Then, four months ago, Ravi heard about Sentient and told the company about his problem. Sentient suggested its Ultimate 1200, which can terminate a T-3 and switch the traffic through to a single OC-3 port occupying one slot on a FORE switch. The hospital bought the Ultimate box for $39,000.

In addition to the T-3s, the Ultimate 1200 handles a group of 56K bit/sec and 64K bit/sec lines running PPP from small remote sites.

The WAN access switch converts a PPP session to an ATM permanent virtual circuit and puts it through to a Cisco router on the LAN.

"We have less equipment to maintain, less space taken up in the data center and fewer cables running around. And we get all the functionality that we need," Ravi says.