I was asked today what the difference between SFP and SFP+ is. I did really know, so I looked it up and it seems that the SFP spec provides capabilities for data rates up to 4.25Gb/s, whereas SFP+ supports up to 10Gb/s. Naturally, this made me wonder whether or not an optic that supported 10GbE always conformed to the SFP+ standard inherently, or if there are cases where a 10GbE optic might only support the SFP standard, thus having a 4.25Gb/s bottleneck.
Jason - there are no SFP-10G parts based off of the original SFP; they all are based on the SFP+ standard, so there will be no issues with the optic not being able to work at the full 10Gbps it's rated for. Sam Chesluk Network Hardware Resale -----Original Message----- From: Jason Lixfeld [mailto:jason@lixfeld.ca] Sent: Thursday, February 17, 2011 3:00 PM To: nanog@nanog.org Subject: SFP vs. SFP+ I was asked today what the difference between SFP and SFP+ is. I did really know, so I looked it up and it seems that the SFP spec provides capabilities for data rates up to 4.25Gb/s, whereas SFP+ supports up to 10Gb/s. Naturally, this made me wonder whether or not an optic that supported 10GbE always conformed to the SFP+ standard inherently, or if there are cases where a 10GbE optic might only support the SFP standard, thus having a 4.25Gb/s bottleneck.
I'm curious also. Could you use a SFP in a ten gig port if you only need 4gb of throughput? Sent from my iPhone On Feb 17, 2011, at 6:25 PM, "Sam Chesluk" <Sam@networkhardware.com> wrote:
Jason - there are no SFP-10G parts based off of the original SFP; they all are based on the SFP+ standard, so there will be no issues with the optic not being able to work at the full 10Gbps it's rated for.
Sam Chesluk Network Hardware Resale
-----Original Message----- From: Jason Lixfeld [mailto:jason@lixfeld.ca] Sent: Thursday, February 17, 2011 3:00 PM To: nanog@nanog.org Subject: SFP vs. SFP+
I was asked today what the difference between SFP and SFP+ is. I did really know, so I looked it up and it seems that the SFP spec provides capabilities for data rates up to 4.25Gb/s, whereas SFP+ supports up to 10Gb/s. Naturally, this made me wonder whether or not an optic that supported 10GbE always conformed to the SFP+ standard inherently, or if there are cases where a 10GbE optic might only support the SFP standard, thus having a 4.25Gb/s bottleneck.
Jason - there are no SFP-10G parts based off of the original SFP; they all are based on the SFP+ standard, so there will be no issues with
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). Sam Chesluk Network Hardware Resale -----Original Message----- From: Jimmy Changa [mailto:jimmy.changa007@gmail.com] Sent: Thursday, February 17, 2011 3:39 PM To: Sam Chesluk Cc: Jason Lixfeld; <nanog@nanog.org> Subject: Re: SFP vs. SFP+ I'm curious also. Could you use a SFP in a ten gig port if you only need 4gb of throughput? Sent from my iPhone On Feb 17, 2011, at 6:25 PM, "Sam Chesluk" <Sam@networkhardware.com> wrote: the
optic not being able to work at the full 10Gbps it's rated for.
Sam Chesluk Network Hardware Resale
-----Original Message----- From: Jason Lixfeld [mailto:jason@lixfeld.ca] Sent: Thursday, February 17, 2011 3:00 PM To: nanog@nanog.org Subject: SFP vs. SFP+
I was asked today what the difference between SFP and SFP+ is. I did really know, so I looked it up and it seems that the SFP spec provides capabilities for data rates up to 4.25Gb/s, whereas SFP+ supports up to 10Gb/s. Naturally, this made me wonder whether or not an optic that supported 10GbE always conformed to the SFP+ standard inherently, or if there are cases where a 10GbE optic might only support the SFP standard, thus having a 4.25Gb/s bottleneck.
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. -- 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)
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. Frank -----Original Message----- From: Richard A Steenbergen [mailto:ras@e-gerbil.net] Sent: Thursday, February 17, 2011 7:00 PM To: Jason Lixfeld Cc: nanog@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. -- 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)
On Thu, Feb 17, 2011 at 09:04:29PM -0600, 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.
It doesn't work that way. The closest you can get is that the device can support either 1G or 10G in the same port (since SFP and SFP+ are physically and electrically the same), but it requires support from the device (since both PHYs have to be implemented). -- 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)
You can plug SFP module (copper or fiber) into any SFP+ port. So, on 10G port you can run either 1GE or 10GE. Peter Nowak _____ From: Frank Bulk [mailto:frnkblk@iname.com] To: 'Richard A Steenbergen' [mailto:ras@e-gerbil.net] Cc: nanog@nanog.org Sent: Thu, 17 Feb 2011 22:04:29 -0500 Subject: RE: SFP vs. SFP+ 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. Frank -----Original Message----- From: Richard A Steenbergen [mailto:ras@e-gerbil.net] Sent: Thursday, February 17, 2011 7:00 PM To: Jason Lixfeld Cc: nanog@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. -- 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)
On Fri, Feb 18, 2011 at 12:55:45AM -0500, Peter Nowak wrote:
You can plug SFP module (copper or fiber) into any SFP+ port. So, on 10G port you can run either 1GE or 10GE.
Not true. Some devices support this, since SFP and SFP+ are physically and electrically compatible, but not all. The device must be specifically designed to support both PHYs, which is NOT a given. -- 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)
On 18/02/2011 05:55, Peter Nowak wrote:
You can plug SFP module (copper or fiber) into any SFP+ port. So, on 10G port you can run either 1GE or 10GE.
A well known counterexample of this is the Cisco Nexus5k, where only some of the SFP+ ports are 1G capable (first 8 on the 20 port box, and the first 16 on the 40 port box). Nick
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) http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps7077/product_da... Vince
Frank
-----Original Message----- From: Richard A Steenbergen [mailto:ras@e-gerbil.net] Sent: Thursday, February 17, 2011 7:00 PM To: Jason Lixfeld Cc: nanog@nanog.org Subject: Re: SFP vs. SFP+
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
On Thu, Feb 17, 2011 at 03:41:28PM -0800, Sam Chesluk wrote: 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.
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) http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps7077/product_da... Vince
Frank
-----Original Message----- From: Richard A Steenbergen [mailto:ras@e-gerbil.net] Sent: Thursday, February 17, 2011 7:00 PM To: Jason Lixfeld Cc: nanog@nanog.org Subject: Re: SFP vs. SFP+
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
On Thu, Feb 17, 2011 at 03:41:28PM -0800, Sam Chesluk wrote: 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.
participants (8)
-
Frank Bulk -
Jason Lixfeld -
Jimmy Changa -
Nick Hilliard -
Peter Nowak -
Richard A Steenbergen -
Sam Chesluk -
Vincent Hoffman