[c-nsp] NPE-G1s don't want to talk to each other over copper?

[Jim Getker (getker)]

Actually during auto-negotiation  one pair transmits fast link pulses and another pair receives them.  The same basic AN protocol is used for 10/100/1000, gigabit just has some additional pages.  So gigabit phys generally do support MDI/MDIX as well as auto-mdix, but the need goes away when link comes up at 1G.

Jim

-----Original Message-----
From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Daniele Orlandi
Sent: Wednesday, March 19, 2014 1:05 PM
To: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] NPE-G1s don't want to talk to each other over copper?

On 03/19/2014 05:45 PM, Lukas Tribus wrote:
>
> Its correct that GigabitEthernet mandates autoneg, and it is also 
> correct that "mdix auto" REQUIRES autoneg, but afaik that doesn't mean 
> all your gigabit/autoneg gear can also automatically do auto-mdix, 
> because that probably requires different hardware (switching RX/TX).

GBE does not have a MDI/MDI-X concept since every pair is used for RX and TX at the same time.

There is no such thing as a "Gigabit crossover cable".

Bye,
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