6

I'm thinking on building my own (micro-atx) router for business and personal projects at home.

My question is what kind of network card do I need to receive the fiber optic connection? I'm currently using the router my ISP provides me but I want to replace it.

I've been looking and I can only find super expensive cards (more than 150-250€) and I think those are not the ones I need, so can anyone point me in the right direction?

I will be using a Linux distro with iptables, dhcp, bind, etc...

Chazy Chaz
  • 329
  • 1
  • 5
  • 15
  • 1
    Obvious question: what's the current router provided? (make and model). Might help us clear up some of the confusion. Is it actually fiber optic to the device, lots of UK ISPs sell "fiber" connections that are FTTC with a VDSL downlink. Much cheaper consumer routers. – pjc50 Feb 14 '17 at 10:11
  • The router is a ZTE F680 (ISP: Jazztel Spain). Unless VDSL can go through a fiber optics cable, I think it's legit fiber, the connector is SC type, what I don't know if it's multi or single mode (neither the upstream/downstream channels). If you didn't read it in a comment below, I can actually see the word PON engraved on the router case surface where the SC port is. But I read a 2 yo article saying that Jazztel moved from GPON to 10Gb PON. – Chazy Chaz Feb 14 '17 at 12:58
  • I can see in the router page, a tab named PON Status with info about ONU state (o5), i/o power, temperature, voltage, bias... But that's irrelevant. – Chazy Chaz Feb 14 '17 at 13:08
  • If the original retail price at http://www.balticnetworks.com/zte-zxhn-f680-dual-band-concurrent-802-11ac-advanced-gpon-gateway.html is accurate ($1500!), it's not really surprising that you're finding it expensive to replicate. – pjc50 Feb 14 '17 at 13:20
  • Well, $1500 yet security sucks... All it took was a symlink in a usb drive to open it. I definitely want to run my own (up-to-date) software. So it's GPON, how do I look for a compatible module? Looking for: `ITU-T G.984.x / G.988 GPON standards` and `Class B+ optical module, Class 1 Laser`? – Chazy Chaz Feb 14 '17 at 13:39
  • Something like https://www.startech.com/uk/Networking-IO/Adapter-Cards/pcie-gigabit-ethernet-fiber-card-open-sfp~PEX1000SFP2 + https://www.finisar.com/optical-transceivers/ftgn2117p2txn I think. Although it would be far easier to put the existing router into passthrough mode and build your own router on the LAN side? (SFP stuff seems to be so specialist that it's not on Amazon!) – pjc50 Feb 14 '17 at 13:47
  • Yeah, I thought about that too, but there's no way to put it in bridge mode! Even though I have root access (anyway it's the ram), I wouldn't know how to do that. What would be the difference with http://www.ebay.com/itm/131847025316? It's half the price and seems better (10Gbps, 2 sfp ports, intel controller vs realtek). – Chazy Chaz Feb 14 '17 at 14:04

5 Answers5

12

You don't want to buy a "fiber card". What you want is a card (or preferably a switch) that has either SFP or SFP+ ports.

This will allow you to purchase cheap optics depending on what you need, and will ensure that you're future-proof if you need to upgrade or change optics in the future.

As for what type of optics you'll need, that's a conversation you will need to have with your ISP. Whatever you have will need to match whatever is on the other end of your fiber pair.

EEAA
  • 108,414
  • 18
  • 172
  • 242
  • 2
    As an aside, [FS](http://www.fs.com/) is a great reasonably-priced outlet for purchasing optics. – EEAA Feb 13 '17 at 21:45
  • So if I switch ISP and it uses a different type I'll need another card? And I thought this was the easy part. I'm going to get some info about the different types and the options I have, thanks. – Chazy Chaz Feb 13 '17 at 22:09
  • 3
    No, read the answer. The point of getting an SFP card is that you can swap out optics if needed. If you switch ISPs and the new one needs different optics, you switch *that* out and the card stays the same. – EEAA Feb 13 '17 at 22:11
  • So what do you mean by your last phrase? Do you mean the cable that the technician installs and plugs in to the router? – Chazy Chaz Feb 13 '17 at 22:15
  • 2
    No, I mean the SFP module that goes into the SFP slot on your card. Research this stuff a bit, it's not complicated. :) – EEAA Feb 13 '17 at 22:16
  • Yeah sorry, english is not my main language. I don't understand what is the SFP module? – Chazy Chaz Feb 13 '17 at 22:26
  • This is something you can easily research on your own. – EEAA Feb 13 '17 at 22:26
  • Sure, i'll get to it. Last thing, why you said preferable a switch? Are the differences better for my use case? Explain just a bit please :) Edit: I was thinking on 1 card for wan and 1 for lan, or wasn't that what you meant by that? – Chazy Chaz Feb 13 '17 at 22:35
  • I'm not going to carry on in comments here. You have your answer, now take the opportunity to go read about modern network design. If you want in-depth education in networking 101, I'm glad to provide it, but not here. I can be contacted at the email in my profile. – EEAA Feb 13 '17 at 22:41
  • 2
    FWIW, a switch is *not* what you want for a WAN connection. Switches do not have feature sets optimized for WAN. Please consider recommending a router (which I took the liberty of editing into your answer) – Mike Pennington Feb 14 '17 at 00:33
  • 1
    @MikePennington The OP wants to *build* a router. I'm well aware that a router must be involved, but in this case I really did mean to recommend a switch (which would more or less function as a media converter in this case). – EEAA Feb 14 '17 at 00:44
  • Switches don't have the buffering or shaping features typically required, even in a media converter role. – Mike Pennington Feb 14 '17 at 00:48
  • So what I need is a GPON SFP module/transceiver and a network card with a SFP port. Is it really that expensive? I've counted more than 200 €... – Chazy Chaz Feb 14 '17 at 00:59
  • @ChazyChaz no, we don't know what kind of SFP module you need. You need to just get an SFP NIC. Yes, they are expensive, because in gigabit form they are not very common. If you find out what kind of connection you need, then you can just buy a card with that type of connection built in. It might be GPON, it might just be regular ethernet. It might be LC or LT fiber. We just don't know. – Mark Henderson Feb 14 '17 at 01:37
  • Hi again, at last, I now know (thanks to pjc50 in the comments above). Any recommendations? Thanks. – Chazy Chaz Feb 14 '17 at 13:41
  • @ChazyChaz Final comment: talk with your ISP. Find out what their requirements are for your router. Product recommendations are off-topic here. – EEAA Feb 14 '17 at 15:24
  • Aren't these http://www.balticnetworks.com/zte-zxhn-f680-dual-band-concurrent-802-11ac-advanced-gpon-gateway.html the requirements for a compatible transceiver? Ok sorry, didn't know, I'll ask for recommendations elsewhere. – Chazy Chaz Feb 14 '17 at 15:41
4

You need to find out what standard your ISP is using before you can start shopping for hardware to connect to it.

IF it's a fiber ethernet variant then you can use a network card with a SFP/SFP+ slot (SFP is for 1 gigabit, SFP+ for 10 gigabit) and a suitable transciever module.

If it's GPON then internal interface cards for PCs don't seem to exist, it seems you have to buy a seperate "GPON modem".

If it is some legacy telco standard you will need different hardware again.

Peter Green
  • 4,056
  • 10
  • 29
  • It's PON, I can see it in the back where the cable is connected, so it seems the modem is embed inside the router. Can't a GPON modem be connected to the mobo? – Chazy Chaz Feb 13 '17 at 23:42
  • Isn't this what I would need? https://www.finisar.com/optical-transceivers/ftgn2117p2cxn Where can I find the cards? I really have no idea how this things work :( – Chazy Chaz Feb 13 '17 at 23:53
  • I could be mistaken (I'm not a GPON expert either) but I think that thing is for the provider-end of a GPON link, not the customer end. – Peter Green Feb 14 '17 at 00:17
  • Isn't convert from optical to electrical signal what the module/transceiver does? What's the difference then? – Chazy Chaz Feb 14 '17 at 00:50
  • 1
    GPON has an upstream/downstream model with a single upstream node serving multiple downstream nodes over a single fiber. Different wavelengths are used for upstream and downstream communications and the upstream end acts as a timing master for multiple downstreams. – Peter Green Feb 14 '17 at 01:16
  • From some further googling though it seems my previous comment about the device you linked was mistaken. It seems it is in fact a downstream device. – Peter Green Feb 14 '17 at 01:19
  • So that means it's a GPON module what I need, I just find out the exact info needed to buy a compatible one (in the comments above). Thanks! – Chazy Chaz Feb 14 '17 at 14:08
0

But you can’t just plug in a gpon sfp module into a switch first you then are straight connected to the wan and that is unsafe and second most of the time your isp needs to put your sfp module or ont’s s/n into the config of the olt at your isp’s fiber hut

Miles
  • 1
0

Cause i used a super micro router with a chelsio t420CR with a Nokia class 1 3FE53441AA 01 NIB and worked fine i just needed to call my isp and say the s/n of the sfp module and it worked

Miles
  • 1
0

The easiest way is to configure the ZTE F680 in bridge mode. That way the TV and telephone ports on the F680 will still work (if you use those services). The F680 will bridge the Internet VLAN to its LAN ports and you can just connect a typical Ethernet router's WAN port to it.

If you want to bypass the F680 altogether, you need a GPON Class B+ ONT/ONU SFP module (not Class C++, not OLT) such as the Finisar FTGN2117P2CxN or the ZyXEL PMG3000-D20B. You can plug this into an SFP port on a router or switch and use the same Internet VLAN ID that your ISP has configured on the ZTE F680.

You cannot easily change the SN / Password / LOID on GPON ONT SFP modules, and ISPs use these values to prevent the use of unauthorized ONTs. Unless you can get your ISP to whitelist your SFP module, you may be forced to use bridge mode with their CPE.

Monstieur
  • 536
  • 2
  • 15
  • ZTE F680 does not support a bridge mode. I have such a router. – Ely Aug 17 '17 at 13:24
  • @Elyasin It is not explicitly called bridged mode. If you leave the PPPoE unconfigured I believe it bridges the Internet VLAN automatically. – Monstieur Aug 17 '17 at 16:47
  • That would be interesting. Any links or documentation about that? I'm still in doubt. – Ely Aug 17 '17 at 17:20
  • The F680 is not listed on this page, but it should behave the same as the rest which bridge by default. I believe you do need to specify which are the Internet and telephone VLAN IDs for it to work. http://wwwen.zte.com.cn/en/products/access/xpon/201301/t20130131_385569.html – Monstieur Aug 18 '17 at 06:37