ATM Chip Grows From AS/400 Roots

At a time when the volume and diversity of network traffic threatens to transform IT infrastructures into freeways of frozen information, IBM Microelectronics hits the streets with its ATM resource management chip – an integrated subsystem designed to manage large amounts of remote, voice and video data.

Based upon asynchronous transfer mode (ATM) technology, this new chip operates as a traffic controller, enabling the simultaneous partitioning of bandwidth for more than 65,000 network connections for server, switch, network node and user node interface applications and SONET-based systems, according to IBM.

The technology behind the ATM resource management chip now available was originally conceived as a way to sharpen the memory capabilities of the AS/400. "This chip today is the follow-on to the current AS/400 ATM PCI card," says John Shaffer, advisory engineer for IBM Server Group. "This chip is actually somewhat of a hybrid. The AS/400 chip does all the ATM function on the chip, while the follow-on has the addition of a PowerPC core on the chip, right there on the silicon."

Building upon the AS/400’s basic chip technology, IBM has added an on-board PowerPC core for available bit rate (ABR) support, enabling users to mutually define required bandwidth for a given communication or transaction across networks. The ATM resource management chip also has two independent memory controllers (each supporting up to 128 MB of DRAM or 8 MB of SRAM), integrated PCI bus interface with programmable burst length, AAL 5 processing that minimizes host involvement, three direct memory access (DMA) channels with host memory cut-through and TCP checksum generation and checking, and event generation and queuing mechanism for minimizing interrupted processing.

The new chip is architected to plug into the PCI bus of a system, according to Dick Bains, IBM distinguished engineer for IBM Server Group. "Some of the AS/400 product line, and very shortly all of the AS/400 product line, will have PCI bus capability," he says. "On the card is the integrated ATM technology along with the PowerPC that allows more flexibility in manipulating the ATM protocol."

"ATM is a very versatile protocol," Shaffer says. "The new card represents a progression in ATM technology, in our effort to increase network bandwidth availability to applications and the ability to control networks and be able to use them effectively and efficiently."

Users are required to have an ATM driver on their server to make use of the new chip, according to Bains. "You will see drivers for the RS/6000, and possibly the S/390 and Netfinity, because they basically have an open interface to install the drivers," he says.

"This is an example of a development effort out of the AS/400 team, but it’s really for the IBM team as a whole," Bains adds. The AS/400 market will likely have to wait longer than other IBM server markets. "Because of the integrated nature of the AS/400, it usually takes us a little time to put the integrated drivers into the system."