On Sun, 7 Nov 2010 01:49:20 -0600 Richard A Steenbergen <ras@e-gerbil.net> wrote:
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. :)
That sounds a lot like the "Worse is Better" argument The Rise of ``Worse is Better'' http://www.jwz.org/doc/worse-is-better.html This quote would be quite applicable to Ethernet - "The lesson to be learned from this is that it is often undesirable to go for the right thing first. It is better to get half of the right thing available so that it spreads like a virus. Once people are hooked on it, take the time to improve it to 90% of the right thing." I think ethernet gaining OAM would be an example of improving to 90% of the right thing (15 or so years after being invented and deployed), while those technologies that tried to be right from the outset (token ring, ATM etc.) have or are disappearing.