SFP breakout to another SFP - Page 1
Forum section: electronics / projects

author: Stealthrt
author_rank: Regular Contributor
timestamp: August 07, 2016, 04:37:41 pm
content: Hey all I am just wondering before I do this if its possible to connect 2 SFP sockets to each other in order to bring in the fiber connection and then take it back out the same way?So in the image above, Pin 1 would hook up to Pin 1 on the second SFP socket. Pin 2 would hook up to Pin 2 on the second SFP socket, etc etc...I'm doing this so that I can bring in the SFP connection into a server case and then once inside the server case I need to hook it up to a motherboard inside there that has the SFP connection.

author: kc8apf
author_rank: Regular Contributor
timestamp: August 07, 2016, 04:55:11 pm
content: No. Most SFP modules have active electronics in them. They need power and I2C connections to program and enable the optics.Sent from my Nexus 5X using Tapatalk

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 07, 2016, 06:03:41 pm
content: So add a microcontroller and DC power socket?

author: Stealthrt
author_rank: Regular Contributor
timestamp: August 07, 2016, 06:15:00 pm
content: To better illustrate what I am trying to accomplish:

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: August 07, 2016, 08:35:48 pm
content: Get a direct attach cable, and make a small board that has two SFP cages and does a 1:1 match (but swap TD and RD) between the pins on each cage. A direct attach cable implements a TD/RD pair swap, so your board will need to reverse that swap so you can plug in an SFP module. You will also need to provide power to the SFP+. According to the data sheet for a DAC, only the TD/RD pairs are wired, everything else is left open:http://www.molex.com/pdm_docs/sd/739290001_sd.pdfMake sure the connections are controlled impedance and routed as differential pairs, the signals passing through are very high bandwidth (1.25 Gbit/s).Given all the trouble this takes, my suggestion (if you can't re-orient the server board to expose the SFP cage on one edge) is to use copper Ethernet and an external media converter.

author: Stealthrt
author_rank: Regular Contributor
timestamp: August 07, 2016, 08:53:09 pm
content: thanks radar_macgyver. would you be able to digikey link those things I need?Sent from my SM-N920V using Tapatalk

author: Stealthrt
author_rank: Regular Contributor
timestamp: August 07, 2016, 11:03:27 pm
content: this is what the ONT fiber hook up looks like that I am wanting to use (green connector).

author: Monkeh
author_rank: Super Contributor
timestamp: August 07, 2016, 11:07:08 pm
content: Why not just couple the fibre in instead of messing around with SFPs?

author: Stealthrt
author_rank: Regular Contributor
timestamp: August 07, 2016, 11:11:25 pm
content: Quote from: Monkeh on August 07, 2016, 11:07:08 pmHave an example from Digikey that you could point to?

author: Monkeh
author_rank: Super Contributor
timestamp: August 07, 2016, 11:12:19 pm
content: Quote from: Stealthrt on August 07, 2016, 11:11:25 pmHow about a keyword: LC-LC coupler. SC-SC coupler. Insert-fibre-termination-here coupler.

author: Monkeh
author_rank: Super Contributor
timestamp: August 07, 2016, 11:13:45 pm
content: Quote from: blueskull on August 07, 2016, 11:13:03 pm.. no, I mean a panel coupler..

author: Stealthrt
author_rank: Regular Contributor
timestamp: August 08, 2016, 02:07:07 am
content: Quote from: blueskull on August 07, 2016, 11:16:15 pmSo something like this?http://www.showmecables.com/product/SC-Female-to-SC-Female-Ceramic-Fiber-Optic-Adapter.aspx?utm_source=google&utm_medium=cse&utm_campaign=ICFOA8SM01&gclid=CLu08ITdsM4CFYKCaQodiZoJzg

author: Monkeh
author_rank: Super Contributor
timestamp: August 08, 2016, 02:08:49 am
content: Quote from: Stealthrt on August 08, 2016, 02:07:07 amExactly. Whack that on your panel, plug your SFP in internally, patch a short piece of fibre between them. Job done.

author: Stealthrt
author_rank: Regular Contributor
timestamp: August 08, 2016, 02:11:48 am
content: Quote from: blueskull on August 07, 2016, 11:13:03 pmNope not in NC. Trust me, I would take you up on your offer if i was

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: August 08, 2016, 02:22:39 am
content: Panel coupler is the way to go, forget everything I wrote

author: Stealthrt
author_rank: Regular Contributor
timestamp: August 08, 2016, 02:25:02 am
content: Quote from: radar_macgyver on August 08, 2016, 02:22:39 amForgotten

author: RJFreeman
author_rank: Regular Contributor
timestamp: August 08, 2016, 02:49:14 am
content: Should just point out: Green suggests it is an Angled SC connector or SC/APC (which would be consistent with it being used on GPON ) so ideally you will need an Angled SC connector and patch leads.Just checking the vendor you linked to before I can only find an appropriate duplex (two fibre) coupler:http://www.showmecables.com/product/Duplex-SC-APC-Female-to-SC-APC-Female-Single-Mode-Adapter.aspxof course there is nothing to say you have to use both sides....