topic SR203 Router Purple socket vs Yellow socket no. 4 in Broadband

SR203 Router Purple socket vs Yellow socket no. 4

David382 — Mon, 24 Nov 2025 16:51:51 GMT

Getting ready for activation tomorrow and instructions say use yellow no. 4 for connection to ONT.

So what is the purple socket for?

Re: SR203 Router Purple socket vs Yellow socket no. 4

TimmyBGood — Mon, 24 Nov 2025 18:05:41 GMT

@David382 wrote:

So what is the purple socket for?

An RJ11 connection from a 'phone' socket for ADSL, FTTC and (possibly ) G.fast broadband i.e. metallic circuits. It goes to a VDSL modem chipset within the Hub.

This isn't required for FTTP because it's the ONT which performs the 'modem' (or more accurately transponder) function.

Re: SR203 Router Purple socket vs Yellow socket no. 4

David382 — Mon, 24 Nov 2025 18:29:16 GMT

So I think what your answer means the yellow no. 4 is for full fibre as I have and the purple was for when a couple of years back pre full fibre and copper wires were to my house.

Shame the purple can't be used as I would have liked to have used yellow no. 4 along with 1 to 3 for ethernet connections.

Lets hope the next design of router has a seperate WAN socket to give back 4 sockets to use when copper wires for BB/telephone were in use.

Thanks for your answer.

Re: SR203 Router Purple socket vs Yellow socket no. 4

TimmyBGood — Mon, 24 Nov 2025 19:46:21 GMT

@David382 wrote:

So I think what your answer means the yellow no. 4 is for full fibre as I have and the purple was for when a couple of years back pre full fibre and copper wires were to my house.

That's correct.

Shame the purple can't be used as I would have liked to have used yellow no. 4 along with 1 to 3 for ethernet connections.

It's not physically or logically possible to route ethernet from an ONT into a modem socket: they are talking different languages. An unmanaged gigabit ethernet switch is the appropriate hardware to provide additional RJ45 ports.

Lets hope the next design of router has a seperate WAN socket to give back 4 sockets to use when copper wires for BB/telephone were in use.

That will typically be the case as FTTP speed increases: the Sky Gigafast+ Hub for 2.5Gbs and 5Gbs over CityFibre infrastructure has a 10Gbs WAN port for the ONT plus four ethernet ports (1x10Gbs and 3x1Gbs)