On Sun, Nov 07, 2010 at 08:02:28AM +0100, Mans Nilsson wrote:
The only reason to use (10)GE for transmission in WAN is the completely baroque price difference in interface pricing. With todays line rates, the components and complexity of a line card are pretty much equal between SDH and GE. There is no reason to overcharge for the better interface except because they (all vendors do this) can.
To be fair, there are SOME legitimate reasons for a cost difference. For example, ethernet has very high overhead on small packets and tops out at 14.8Mpps over 10GE, whereas SONET can do 7 bytes of overhead for your PPP/HDLC and FCS etc and easily end up doing well over 40Mpps of IP packets. The cost of the lookup ASIC that only has to support the Ethernet link is going to be a lot cheaper, or let you handle a lot more links on the same chip. At this point it's only half price gouging of the silly telco customers with money to blow. There really are significant cost savings for the vendors in using the more popular and commoditized technology, even though it may be technically inferior. Think of it like the old IDE vs SCSI wars, when enough people get onboard with the cheaper interior technology, eventually they start shoehorning on all the features and functionality that you wanted from the other one in the first place. :) -- Richard A Steenbergen <ras@e-gerbil.net> http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)