GSC3570 dual network ports - options for connecting to GDS3710


We have a GDS3710 intercom unit at a remote gate on our property. It is connected to a network switch in a far room of our house with a PoE injector just after the switch. Until now we have been taking calls (bell push) from the GDS3710 on PCs wired into the network or mobile phones via wifi.

Have just purchased a GSC3570 unit that we will install in the kitchen which is at the ‘near end’ of the house.

We have cat6 cable running: Switch > PoE injector > through internal wiring to the kitchen > then outside for ~80m to the GDS3710 at the gate.

There is a join in the cat6 cable in the kitchen at the point where we want to install the GDS3710 control unit (the wiring was installed for an older system 12–15 years ago, before we bought the house).

My question is … can we ‘cut’ the cat6 cable at the existing join and plug the cable coming from the switch & PoE injector into the “PoE” RJ45 port on the GDS3710, and the other part of the cable that continues out to the gate into the second RJ45 port on the GDS3710. So the final arrangement would be

Switch > PoE injector > ‘PoE’ RJ45-GSC3570-RJ45 > GDS3710

This would greatly simplify installation of the GSC3570 if it can work that way. We have concrete block exterior walls and a concrete floor slab and it would be very difficult to change or add further internal cabling.

Ideally the GSC3570 should bridge power from the injector through to the gate unit as well as providing separate Switch to GDS3710, and Switch to GSC3570 data links. Plus power the GSC3570 of course.

We want it all to go back to the switch so we can continue to respond to the GDS3710 on our mobile phones (via wifi)

My reasons for thinking (hoping!) it can are:

  • the GSC3570 documentation describes them as dual switched network ports
  • that it would be an obvious use case for the dual network ports?
  • one option we investigated previously was an Akuvox IT82R control station/monitor. That also has “dual switched network ports” and the Akuvox agents confirmed to us that the arrangement described above will work with the IT82R (& indeed is an intended application)

My reason for fearing it might not work is that none of the Grandstream documentation and application examples I have seen show the GDS3710 and GSC3570 connected this way. Almost all examples show the GDS3710 and GSC3570 independently connected to a switch via separate network cables or wifi links.

Would very much appreciate clarification on the above.
Many thanks


David, both units need power and have to be powered independantly. So POE + Ethernet for one device and POE + Ethernet for the other.

Perhaps you may be able to hide a POE injector at the GSC3570 that will power the GDS3710 and have a POE injector at the switch for the GSC3570 - that may work well with the ethernet switch in the GSC3570.


Many thanks Kevin. The data switching is the most important aspect for us. We do have a couple of other options for providing power to the GDS3710 though the switching in the GSC3570 would have been the neatest solution. If the two ports are fully switched, would the power not pass through anyway?

We can put an injector in the wall at the kitchen but I feel uncomfortable at the thought of having a power brick enclosed within the wall. There is already a power brick there from the old system - I just do not like the idea from a fire risk POV.

A better alternative is that the cat6 goes through an outside shed (pool pump house) on it’s route to the gate. There is mains power in the shed. We also have mains power at the gate (gate open control and actuators etc)… So we can put an injector at either location or even power the GDS3710 separately at the gate. I just liked the idea of using the one injector to power both unit (the injector should have adequate capacity for that). Already so many small power bricks for this that and the next thing!

Almost tempting to manually bridge the power wires in the cat6 (ie. behind the GSC3570, bridge from the cat6 into the GSC3570 to the outgoing cable)! Probably a bit untidy but we know which wires carry the power so it should work fine??? I suspect not something experts would recommend though :frowning:.

Your reply gives me a bit more confidence that the data switching will work so we will proceed with installing and deal with the power as seems best at the time. Most likely will inject in the pump house as there is already a join in the cat6 there (the original cable only went that far. We extended it out to the gate).

Again, many thanks for your quick reply


I am not quite understand your wiring and connection. But if both GDS3710 and GSC3570 connected to the same LAN, and if the strike is controlled by GDS3710, then you can configure secure open door (both GDS3710 and GSC3570 should use latest firmware) so that GSC3570 can open door (with or without phone call).

If your GDS3710 can have power and connected to network, then the GSC3570 can power via 2A 5V USB and connected to WiFi, no network cable needed.

There should be HOWTO guide in the product information page or configuration example in the firmware release note.

Hope this helps. Thank you for using GDS3710/GSC3570 open door combination solution!


Perhaps something like this within the wall behind the GSC3570 would be better?

Only reservation is that may need PoE+ in to provide 10w each out port?

I guess only question on this is whether the GDS3710 and GSC3570 units would work OK with ~7w power to each?


Thanks for the response. To clarify the envisaged interconnection between the two units & the network switch, the the diagram below.

Alternative with the IPCAMPOWER device or similar would be like this

Attraction of this type of device is that it is quite small (3" x 3" x 1") so would easily fit in the wall behind the GSC3570


@David_NZ: Both GSC3570 and GDS3710 is using 12Watt, so if you are using PoE, make sure the port of the PoE can provide that power otherwise the device will NOT function correctly. And the Data Sheet clearly mentioned Class 3 PoE, which means max. power 12.95Watt provided.
GSC3570: 5VDC, 2A; GDS3710: 12VDC, 1A.

The first drawing should work, because GSC3570 itself the two RJ45 ports is a two port switch/relay, if the GDS3710 connected to the right RJ45 port has own power supply (example: 12VDC, min. 1A Power Adapter).
The PoE injector just provide power to GSC3570 as well as IP; and GDS3710 connect to network and get IP via GSC3570 from the switch/router, but GDS3710 has to have its own power from another power source. GSC3570 can NOT provide power to the GDS3710.

The diagram two theoritically will work as per the wall mount device designed. But in reality should be the INPUT PoE (injector or PoW switch). The output is two 12Watt device, meaning the Input should be AT LEAST 25Watt. I am not sure what kind of PoE Injector your are using, better check the technical specifictaion of the injector. That means the PoE injector or the port of the PoE switch should at least be Class 4 or above high power device (which usually very expensive).

Or another way is use two PoE injector, one before GSC3570 to power GSC3570; another after it to power GDS3710, as the Diagram 1 drawing. Such kind of Class 3 (12Watt) PoE injector is very popular in the market and cost about $20.

More PoE related power information, please check out:

Hope this helps. Thank you for using Grandstream products.


The distance from the house to the GDS3710 is about 80 meters, what is the distance between the GSC3570 to the switch? If the distance from the switch to GDS3710 is less than 100 meter, you can use PoE injector power the GDS3710 from the switch directly, similar to what GSC3570 is powered.

But if the distance is more than 100 meter, then use two PoE injectors one before GSC3570 and one after GSC3570 is good because the distance is around 80 meter (less than the maximum 100 meter ethernet can run).

Using the device from Amazon also working, at least for the wiring and connection, provide the device can provide 12Watt to EACH of the two ports (meaning the INPUT of the device should be at least 25Watt).

Hope this helps.


Thanks for the helpful replies John. Our current PoE injector supplies up to 15w so based on your replies will not power both devices, however configured. I had hoped that though the spec was for 10w per device, 15w would be adequate for the two on the assumption that both units would rarely draw max power at the same time - especially since we are not powering any secondary devices off the GDS3710*. But have concluded that we will need to add a PoE injector after the GSC3570, or possibly power the GDS3710 independently from supply at the gate.

Solution I am now favouring is to take the existing injector and put it in the outside shed between the GSC3570 and the gate. Will then likely get a 5 port PoE+ switch for between the main switch and the GSC3570. An Edimax Web Smart GS-3005P or similar would seem to fit the bill. Yes it costs quite a lot more than a simple PoE injector (or even a small standard PoE switch) and is probably overkill (up to 30w per port) but it seems a better bet in terms of future ‘proofing’. We have a second cat6 cable out to the gate for an IP security video cam sometime in the future. Initially reluctant to get a second switch as our main network switch is already overkill (Netgear Prosafe 24 Smart Switch - only about a third of the ports used currently). But unfortunately no PoE ports.

Incidentally, total length of cable from the existing PoE injector near the switch to the gate is a bit less than 100m. Currently the PoE injector is powering the GDS3710 fine.

(* There is a secondary basic RFID reader for opening the gate when leaving the property. That is connected (RS485?/Wiegand?) to the GDS3710 but it is powered independently. Works fine).


@David_NZ: The " Exit" RFID card should be Wiegand as GDS3710 does not support RS485.

Because most of such device will not use Gigbit ethernet, so I think 100Mbps PoE switch should be fine, and you reserve future expansion of IP cameras is definately good idea.

I checked online and seems this small non-managable PoE switch should do the job fine:

The total power is 60Watt, this means you can power 4 device with max. 15Watt or only 2 device with max. 30Watt. It boasted can support 30Watt, but it can NOT support all 4 port to be 30 Watt (that will add up to max. budget 120Watt consumption). But most of the IP cameras will be 12Watt or so. The 5~7 Watt is most by IP audio phone, and most 7" inch screen video IP phone will use 12Watt, like GSC3570.

Hope this helps. Thank you very much for using Grandstream products.


Many thanks. Yes that is a bit cheaper than the Gigabit managed version of the switch I referenced. Alas I already ordered the Gigabit one. Not a big cost difference though (~US $20 for prices of the two here in NZ) - will get over it.!. Have to confess I assumed a 4k IP security camera would need better than 10/100 ethernet. But on checking I see you are correct. A couple I just checked the spec for indeed only had 100 Mb/s connections. My bad!

One added question re the GSC3570 if I may though. All the docs state that it is ONVIF Profile S but the other thread I posted in suggests that GS has not activated ONVIF in the GSC3570. Indeed appeared that there was no intention to activate ONVIF. I realise the thread is from 8 months ago but nothing was posted to say the situation had changed. A bit of a concern as the specs clearly state ONVIF Profile S interoperability.

Oh, apologies. I see you did reply to my question in the other thread. I did not get email notification of the reply - or perhaps it is in the same email thread as notifications of replies to this thread & I didn’t notice it … Still to digest the reply but no need to reply here as well. Will look into the situation once I do get a IP camera - likely still a good few months off. Thanks

Forgot to add. Confirmed with my son who installed the secondary RFID reader - yes it is Wiegand. Thanks


A brief update. Finally have the GSC3570 installed and working. Can confirm that the dual RJ45’s on the GSC3570 work faultlessly as a switch, as per the working installation shown below. The RPi SIP server is not necessary - added only to get calls out to more than 4 devices. Have it set up so bell push from the gate goes initially to the GSC3570, then if not answered in time, to the SIP server. Call group in the SIP server includes the GSC3570 in case the initial call was just missed. SIP server has a few downsides; eg. lose the gate open button once it comes back from the SIP server, so have to manually dial the code to open the gate.

Will probably add another GSC3570 in the office since spend more time there than in the kitchen! Will be included in the GDS3710 call group (before the SIP server). Otherwise the existing setup is working fine. Credit for setting it all up belongs to one of my sons.

Would be great if the GDS3710 call group was not limited to 4 numbers!! Even better if the switching RJ45 ports on the GSC3570 passed on power as well as data. Would have preferred not to have a PoE injector in the shed.

Would be good to include use of the dual RJ45 ports in this way as an illustrated example on the Grandstream website. If there is already one, I did not find it.


@David_NZ: Thank you for your project update and glad to know everything is working.

Yes, if have your permission, will advise Grandstream document team to have this dual RJ45 application example of GSC3570 in the document to help more customers.

For GDS3710, the 4 numbers are limited to IP address (direct IP call) or extension in parallel hunting call only without PBX involved, because no IPPBX involved and GDS3710 only support 4 SIP accounts/profile, it is a hacking implement not really hunting because GDS3710 itself is SIP Client not SIP Proxy/Server. Most customers who have SIP Server or IPPBX will configure this hunting group at server side and only give hunting group number to GDS3710 doorbell, therefore use maximum 4 different hunting group numbers in two ways (usually more than enough), where the hunting group can have as many phone or extension as the usage application needed.

That said, I will send your request to DEV team to see whether GDS3710 can do more.

Thank you for using Grandstream products!


Yes, it is fine to use this as an example application of the GSC3570. I am sure your documentation team will be able to produce a lot neater diagram!. Perhaps also show a second GSC3570 (optional) attached to the PoE+ switch in the office. If do include the (RPi) SIP server best to make clear that it is optional.

Or perhaps better, one example with the bare minimum hardware to make clear that do not need a SIP server or second GSC3570. Otherwise novices like us could read it as needing a SIP server etc and be overwhelmed before we even started. Then a second example with the SIP server and second GSC3570 to show the possibilities.

We found the existing example applications useful but having one explicitly showing use of the dual ports in this manner would have helped a lot.


@David_NZ: Will do accordingly, thanks for the approval.

Again, appreciate the feedback and thank you for using Grandstream products.