Slicing Through the Hype of IP Switching

By Joel Conover  Few things are changing faster than the ways we communicate. TCP/IP has emerged as the dominant protocol in corporate networks, thanks to the Internet, intranets and aggressive marketing from Microsoft Corp. And network vendors, in an effort to keep your buying dollars flowing in their general direction, are scrambling to invent solutions to your Layer 3 problems. Staying up to date with these events can be a nightmare. In June, Network Computing's Art Wittmann depicted an IP-switching landscape (see "IP Switching: Battle for the Network High Ground," at www.NetworkComputing.com/811/811f1.html). It's nine months later, and the road map and cast of characters has changed significan tly. Ipsilon Networks and its IP-switching technology have been gobbled up by Nokia. A merger between Ascend Communications and Cascade Communications Corp. has left 3Com Corp. without an immediate WAN strategy for FastIP. Cisco Systems has teamed with IBM Corp. to merge IBM's ARIS and Cisco's Tag Switching into an IETF standard called MPLS (Multiprotocol Label Switching). MPOA (Multiprotocol Over ATM) has come into the spotlight as another Layer 3 switching solution. And in the background, fast, hardware-based IP Layer 3 switches are quietly making a splash in the networking pool. Most of these technologies center around IP traffic, though some Layer 3 switches and MPOA implementations support IPX and AppleTalk. In either case, a barrage of lingo and mesmerizing marketing efforts may leave you, the buyer, confused as to which direction to take. One thing is certain: Many of these solutions will lock you in with a single vendor for at least two years. MPOA, FastIP and Layer 3 switches are not pitted agains t one another in a battle for the high ground--rather, many of them are designed to fit into your existing network. We asked network vendors to give us the scoop on where these technologies will fit in, and to provide us with working solutions we could test in our Real-World Labsý. Three vendors came through: Cisco, with a standards-based MPOA solution designed to drop into an existing Cisco routed network; Newbridge Networks, with its prestandard MPOA solution; and 3Com, with its first FastIP implementation. In addition, we examined how traditional routing and newer ASIC-based hardware routers fit into the overall networking picture. Shortcuts: Beware the Wolf, Red Riding Hood All of the technologies we tested in Network Computing's lab at the University of Wisconsin use cut-through methods, or shortcuts, to enable packets to move through the network faster. The MPOA solutions from Newbridge and Cisco and 3Com's FastIP all start by passing packets through a traditional router that maintains acc ess lists and enforces policy. Once clearance has been granted by the router, a shortcut path is set up through the switched network fabric, permitting higher throughput and removing load from the router.

For the Side Bar on How We Tested Other Features Networking in the 21st Century: The Sky's the Limit By Christy Hudgins-Bonafield Related Links IP Switching: Battle For The Network High Ground