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SFP vs. SFP+

On 18/02/2011 03:04, Frank Bulk wrote:
> Are there are any optics that plug into 10G ports but have a copper or
> optical 1G interface?  There's some equipment that I'm specing where it is
> $10K for a multi-port 1G card, even while I really may only *occasionally*
> need a single 1G port and there's a free 10G port for me to use.

Some of the cisco stuff supports a twingig converter module, One tengig
to 2 one gig (and from there a copper or optical SFP)


> Frank
> -----Original Message-----
> From: Richard A Steenbergen [mailto:ras at e-gerbil.net] 
> Sent: Thursday, February 17, 2011 7:00 PM
> To: Jason Lixfeld
> Cc: nanog at nanog.org
> Subject: Re: SFP vs. SFP+
> On Thu, Feb 17, 2011 at 03:41:28PM -0800, Sam Chesluk wrote:
>> Depends on the switch.  Some, like the 2960S and 4948E, have 1G/10G
>> ports.  They will, however, not operate at 4Gbps (that particular speed
>> was chosen to allow the core components to work for gigabit Ethernet,
>> OC48, 2G FC, and 4G FC).
> 4G SFPs are relatively rare, and only for fibre channel. Multi-rate SFPs 
> that do up to 2.5G (for OC48) are a lot more common, but they cost more 
> than just a simple 1GE SFP. Since all you can do with Ethernet is 1G or 
> 10G anyways, "most" SFPs you'll encounter in the field will be the 
> cheaper non-multirate kind.
> For more information about SFP+, as well as some comparisons between 
> different 10G optic types, take a look at:
> http://www.nanog.org/meetings/nanog42/presentations/pluggables.pdf
> As an update (since this presentation is from Feb 2008), SFP+ is just 
> now finally starting to get into 40km/ER reach territory. Supplies are 
> limited, as they just very recently started shipping, but they do exist. 
> Of course since they moved the electronic dispersion compensation (EDC) 
> off the optic and onto the host board, the exact distances you'll be 
> able to achieve are still based on the quality of the device you're 
> plugging them into. SFP+ is still mostly an enterprise box or high 
> density / short reach offering, and XFP is still required for full 
> functionality.