Unfortunately we don’t have FttH here - and I as I work in a technical position at my local cable operator and have a very satisfactory internet connection, the advantages of fiber wouldn’t outweigh the benefits of being able to do my own support in any event.
So what to do with that SFP+ port?
The obvious application is >1Gbps LAN connection. Not that my NAS maxes out my current 1GbE in any way, but it will let me get the highest iperf throughput on the block
I emailed Turris a few months back about expected throughput and received this reply:
Yes, the SFP data differential pairs are connected to the SoC to a SERDES
interface. The SERDES is utilized by the Ethernet L2 element and Armada 385
datasheet says that it supports up to 2.5 Gbps transfer speed over SGMII
http://www.marvell.com/embedded-processors/armada-38x/ . I haven’t seen any 2.5
Gbps Ethernet SFP module so far and I do not know about the 2.5 GbE support in
mvneta driver in Linux kernel. Maybe there are some patches lying in mailing
lists but our kernel does not seem to support that so far.
We plan to investigate this option in the next generation of Turris Omnia,
because there are metalic PHY chips that support 2.5 GbE and that can be
utilized instead of our current 1 GbE PHY. When we have the support for 2.5 GbE
in kernel, then retro-fitting it for SFP cage is possible, if we have proper
SFP modules. But now we can not make any guarantees. However since Turris Omnia
software is OSS, you are always free to research, hack and conntribute support
for the 2.5 Gbps modules on your own.
So, >1Gbps throughput should be possible, but software support for 2.5GbE isn’t there yet. 2.5GBASE-T is by far the most practical way of getting higher speeds in terms of cabling, but this isn’t a practical exercise - and would require a lot of software work (or waiting for someone else to do it). Moreover 2.5GBASE-T SFP+ modules are rather expensive at the moment, which is a bit much for something purely for fun.
What is available cheaply is optical networking. LC connectors can easily be pulled through residential 5/8" conduits, multimode cable is cheap as are 10GBASE-SR SFPs.
That means the following should be feasible:
- 10GBASE-SR SFP in the Omnia
- 7m of LC to LC 10G OM3 multimode fiber
- 10GBASE-SR SFP in another device, probably a NIC in my home server/NAS - a friend said he might have one to spare for me.
I’ve ordered the above parts from www.fs.com for EUR 39 incl shipping to EU (note: FS is a great and affordable supplier of optical equipment with excellent customer service, but be careful when ordering - very expensive express shipping is chosen by default. Make sure to select normal shipping unless you’re in a huge hurry or you end up paying EUR 25 too much…)
Now, when the SFP is used the WAN Ethernet port becomes inactive - but another port can be assigned to function as WAN instead, as explained here:
At this point in time I don’t have a specific question, but intend to keep you updated on this little experiment. Comments are welcome however