Multiple HDMI extenders on one network

[jarrow]

I've placed two NVR's at a clients house and workplace with about 12 cams on each NVR.

The buildings are connected via a single CAT6 cable but both have their own router with connection to the ISP (to keep the business and private apart). This CAT6 cable is connected to a switch which goes to another private outbuilding but isn't connected to the business network.

They now want to be able to live view both NVR's at the same time in both the house and the workplace, using two monitors at each place.

To get the 'private' NVR HDMI signal to the workplace, I've used these HDMI extenders:

They don't need a dedicated UTP cable but can use the existing network and even pass through multiple switches without problems. This works well.

This is the current simplified network schematic, blue is 'private' CAT6, green is 'business' CAT6 and red is HDMI:


To get the 'private' HDMI signal to a monitor somewhere in the house is easy: just get another HDMI extender receiver (they can have multiple receivers on one transmitter).

Now I'd like to use the same set to go the other way around, from the business/workplace NVR to a monitor in the house, but I think it'll cause conflicts, because there is no channel selection on these extenders.

How could this problem be tackled? Any ideas or experience with this kind of problem?
Are there HDMI extenders which do have channel selection?

 

[SpacemanSpiff]

Any chance these locations use managed switches? If so, you could put one set of extenders on their own VLAN.

 

[jarrow]

Great idea, thanks!

Only the 'Main' switches are managed, the 'Private' switch in the workplace is unmanaged, unfortunately.

Could possibly swap it out for a managed version, or add a small managed switch between them.

Another option could be to pull another dedicated cable for just the HDMI signal to the house, not sure if a pull wire is present though.

 

[DsineR]

Encoders & decoders are IP devices, and should be 'addressable'.
Any UI available with your devices to set IP addys? Then direct traffic as needed for Tx -> Rx devices.

 

[SpacemanSpiff]

Another option could be to pull another dedicated cable for just the HDMI signal to the house, not sure if a pull wire is present though.

If all else fails... Depending on the conduit between the house and the workplace... sacrifice a working cable (already in place) to become a pull wire for 2-3 new cables

 

[bp2008]

I played with similar HDMI extenders many years ago and got as far as writing some very crude software that mimics a receiver in order to stream the video into a PC (the quality of the results were insufficient for my purposes, so I abandoned the project).

Anyway assuming yours operate the same, then they don't offer any configuration, and they probably use multicast to send a high bit rate (30-90 Mbps) MJPEG stream with stereo audio to all subscribed receivers. That is much higher bandwidth usage than you'd want to put on wifi, but for a gigabit wired link, two of them is no big deal and leaves at least 80% of your link capacity for other networking purposes. As long as the cable between buildings is in good condition and capable of gigabit speed, then the best bet is to configure one dedicated VLAN per transmitter as recommended by @SpacemanSpiff. Small managed switches are not very expensive so it should be well worth avoiding the trouble of running another cable.

 

[jarrow]

Thanks for the great answers!

@bp2008 , do you think the following configuration would work? The devices look to be exactly the same as the ones you worked with.
(Btw, the client mentioned there could already be multiple cables in place in that conduit, just not used. That's what the dotted line at the bottom is for, this would isolate both the HDMI and private LAN network)


If there's already 3 cables in place, I'd still need two switches but these can be even simpler unmanaged 5 port switches, right? Then each HDMI signal could have its own isolated network.
Or I could even run the first pair of extenders through the existing switches (Zyxel and TP-Link) and run a second pair on its own cable and a simple unmanaged switch at the other side (most economical route).

 

[SpacemanSpiff]

Diagram looks like a good plan @jarrow. Depending on the other network devices at the workplace and the house, you might be able to simply pass the traffic of all three VLAN's between the GS105's

edit: what diagramming software are you using?

 

[jarrow]

Thank you @SpacemanSpiff !

I'll have to check the amount of cables before deciding what is best.

The diagramming 'software' is the free website draw.io with the 'Network' icons enabled in the lower left corner.

 

[bp2008]

@jarrow Yes, that would work with the right VLAN configuration. From this diagram it is unclear why you are linking the netgear switches to the outside world instead of leaving them isolated (I guess they have other devices connected that you haven't shown on the diagram).

You'd want to make sure the link going directly between Netgear switches includes VLANs A and B, but not C or untagged traffic.

 

[jarrow]

Thanks @bp2008 !

From this diagram it is unclear why you are linking the netgear switches to the outside world instead of leaving them isolated

Exactly, the Zyxel and TP-Link switches have many other connections to them (respectively 24 and 11 ports, not drawn), but it would only be needed if there was just one cable running between the buildings.
If there was another (or if running another is easy enough) I could isolate the switches, like you mentioned.

You'd want to make sure the link going directly between Netgear switches includes VLANs A and B, but not C or untagged traffic.

Why can't I have other/untagged traffic running between them, if the other VLAN's have their own IP addresses and don't allow any traffic outside of their own VLAN?

 

[bp2008]

I assumed you'd be dedicating one link for VLANs A and B, and wanting all the non-HDMI-related traffic to be carried by the second link depicted by a dotted line. If you allowed untagged or VLAN C traffic to pass on the link directly between netgear switches, then you'd be creating a loop in the network. The netgear switches may be smart enough to prevent that loop causing trouble ... but they may not be. I wouldn't be sure without testing.

If you don't have the second (dotted line) link, then you'd certainly want the solid line link between netgear switches to carry all traffic, tagged and otherwise. In any case I am not sure you actually need VLAN C.

 

[jarrow]

I see, the dotted line is to indicate the uncertainty of the second link being available. If it is, the link between the Zyxel/TP-link and the Netgears won't be present.

Thank you for the clear explaination! VLANs are relatively new for me, but VLAN C should be called untagged then.

 

[bp2008]

VLAN configuration can be a bit of trial and error until you really get experienced with them (and I am not yet), made worse by the fact that different switch manufacturers use different configuration interfaces. Be sure to look at the documentation for your switch to help learn how it works.

For example this is how it looks on TP-Link:




In this configuration, VLAN 1 owns ports 1-6. VLAN 100 owns port 7. None of the devices connected to ports 1-7 are VLAN-aware; all the traffic entering or exiting those ports is "untagged".

Both VLANs share port 8. Port 8 is the only port that actually receives or sends packets with VLAN tags on them. So if a packet comes in on port 8 and it doesn't have a VLAN tag, the packet is dropped. If the packet is tagged as VLAN 100, then the only place that packet can go is to port 7. If the packet is tagged as VLAN 1, then it can exit via ports 1-6.

I hope this is more clarifying than confusing.