Potentially Useful Network Equipment

Info about hardware we are considering using.

Dell Powerconnect 6248

This is one of a new (Fall 2006) fixed switches that support 4 uplink/10GE ports, 48 1GE ports, the usual management features, Jumbo frames, and Layer 3 switching.

http://www.dell.com/content/products/productdetails.aspx/pwcnt_6248

User's guide available at http://support.dell.com/support/edocs/network/pc62xx/en/UG/PDF/UGA01EN.pdf also local at http://hep.pa.msu.edu/people/rockwell/files/dell-poweredge-6248-users-guide-UGA01EN.pdf

Uses external redundant power supply Powerconnect RPS-600 which powers 4 switches. I couldn't find a reference for the length of the DC power cables that this unit uses.

The switch has two slots for expansion modules on the rear. Modules are available for stacking, cx4, and XFP optics. Each module has two ports. So a single stacking module provides both ports needed for the ring stacking topology, and the cx4 and XFP modules support 2 10GE links.

Stacking

User's guide says that up to 12 switches may be stacked for a total of 12*48=576 1GE ports in the stack.

Guide talks about short (1m) and long (3m) stacking cables. It isn't clear if there is a limitation on the number of long cables used per stack. The stacking cables form a ring; the last switch connects back to the first in order to complete the ring.

thoughts about layout... switches in racks... number of ports per rack... cabling machines in one rack to a switch in another...

One un-fun feature of stacking is that to use a serial connection to a stack, you have to plug the serial cable into the master. A work around is to set a preferred master for the stack.

XFP

At MSU, one switch would have an XFP module and optics to support the fiber link to the outside.

CX4

CX4 is a copper cable that uses 2 thin coax conductors. It supports 10GE links. It is much less expensive to use than fiber. CX4 cables are available to lengths of 12m (any longer?); long enough for any connection in a smallish machine room.

Force10 makes a fixed 24 port 10Ge switch with cx4 ports http://www.force10networks.com/products/s2410.asp It is less than $10K; presumably other vendors will sell similair switches, a primary market for them is iSCSI SANs...

HP Procurve 2900

http://www.hp.com/rnd/products/switches/ProCurve_Switch_2900_Series/overview.htm

-- TomRockwell - 25 Jan 2007