[c-nsp] Full Duplex

[Daniel Roesen]

On Sat, Nov 22, 2014 at 09:43:03PM +0200, Mark Tinka wrote:
> What is more confusing is when vendors use half-duplex 
> bandwidth to make a line card seem faster, e.g., a 30Gbps 
> line card is sold as a 60Gbps if traffic flows in only one 
> direction.

Well, that depends. Lets assume the linecard in question has four 10GE
Ports, but the chip on the linecard driving these ports can only pump
roughly 70Gbps of traffic - no matter what direction. Would you describe
this as a "35Gbps linecard"? Even if you can e.g. do 40G RX + 20G TX,
which would be "line rate" if your traffic profile is heavily and
deterministically biased in one direction?

As long as the vendor is _clear_ what performance exactly is being
claimed, I have no issues with that. In fact, this can be the more
precise number.

All this "n Gbps per Slot" stuff should go away. Vendors should clearly
describe their architecture (fabric, backplane connectivity, traffic
handling chips) and their specific performance characteristics. Blanket
statements seldom tell the full truth.


Best regards,
Daniel

-- 
CLUE-RIPE -- Jabber: dr at cluenet.de -- dr at IRCnet -- PGP: 0xA85C8AA0