Despite gloomy market, vendors keep pumping them outWe hear all the time about the high barriers of entry into the core router space: the time, money and intellectual manpower to invest in a high-end product that faces a long sales cycle into a carrier customer base that by some accounts has halved its capital budget from a year or two ago.But that doesn't deter vendors from trying to chip away at what Cisco and Juniper have erected as they trod through the dusty marrow of the skeletons that were once Lucent's, Nortel's and Pluris' attempts to scale the core router wall.The latest entrants in Survivor - Island of the Giant Routers, are Alcatel, with its second attempt, and start-up Chiaro, which has quietly been forging its tools in stealth mode until this week.Alcatel is respinning its 7770 Routing Core Platform, an ambitious attempt at terabit scale first announced in late 2000 and shipped in mid-2001. Trouble is, carriers shipped it back, claiming the 640G to 5 terabyte\/sec system's footprint was a little too wide and a little too deep for their equipment racks.Alcatel scaled the 7770 down into a half-rack system that it now calls the 7770 Optical Broadband Exchange (OBX). Alcatel also scaled down the system's bandwidth sights to 100G bit\/sec of line capacity and a 320G bit\/sec switching fabric per half-rack shelf.Alcatel says this design makes the router more versatile as well, enabling it to support smaller core and edge applications in addition to large core requirements.Alcatel's OBX retains the 7770's distributed switching and forwarding architecture, and cards from the Routing Core Platform are forward compatible with the OBX, company officials claim. Alcatel claims its mysterious ACEIS fault-tolerant routing technique provides five 9s reliability in a single system - no duplicate router is necessary for redundancy - and that nine racks of line cards, switching and control shelves will bring you 1.9T bit\/sec of line capacity and over 5T bit\/sec of switching.Chiaro didn't provide much product detail on its Enstara router, but it's developing an optical crossbar switch that leverages optics to switch packets internally between line cards. It has been issued patents for its Optical Phased Array approach to switching packets, which uses scores of gallium arsenide optical waveguides in parallel to refract light, under electrical stimulation, from a single ingress fiber to multiple egress fibers.Chiaro's router will also feature five 9s reliability without necessitating a redundant router, officials say, through a technique called Stateful Assured Routing (STAR).Chiaro was tight-lipped about how STAR actually works but it is designed to provide non-disruptive routing protocol switchover in the event of potential outages caused by protocol resets and route convergence times. It does this, Chiaro officials claim, by maintaining TCP state and sessions during resynchronization.Failover is undetectable by a Chiaro routing peer, it claims, and packet forwarding is uninterrupted.Chiaro promised to unveil more product details, along with a customer deployment, early next year.Enstara and OBX will be the latest chisels to scrape away at a market barrier erected by Cisco and Juniper that No. 3 player Avici has made less than a 3% dent in and that a handful of others - Hyperchip, Procket, Caspian and Charlotte's Web, to name a few - are likewise trying to bring down. All for a piece of a pie valued at only $2.1 billion in 2005 from $1.3 billion this year, according to Avici.Which will be the next to join Lucent, Nortel and Pluris as cast-offs or casualties from the Island of Giant Routers?