Hi,
I’m assisting a client in troubleshooting a wireless LAN comprised of Canopy BH20 gear. I didn’t participate in the original setup. I don’t know which of the BH20’s are master and which slave. Nor do I know what the settings of these devices are. All I know is that the original technicians set up the equipment, aligned the parabolic antennae, tested the links and walked away…
The following picture illustrates the layout. Basically it consists of two independent point-to-point links, that is, from Site “A” to Site “B” and from Site “A” to Site “C”. It’s important to clarify that there are two BH20’s at Site “A” [u:2y2jrrwx]side by side[/u:2y2jrrwx] sharing the same pole. One connects to its counterpart at Site “B” and the other connects to its counterpart at Site “C”. So, 4 BH20’s in total for two independent links. Both lines of sight are OK.
[u:2y2jrrwx]Here’s the problem:[/u:2y2jrrwx]
The client claims that both wireless links disconnect and automatically re-connect randomly several times a day. In order to collect some metrics I set up a monitoring workstation at Site “A”, which basically polls every 60 seconds via PING probes all network devices (local and remote, wired and wireless) such as Windows Servers, routers, and the Canopy BH20’s as well. This is what I found: Link A-B suddenly disconnects, stays down for 2 minutes and then re-connects. As soon as A-B re-connects, A-C disconnects, stays down for 6 minutes and then re-connects. Both links stay up for 60 or 70 minutes and then the cycle repeats in that order, that is, link A-B disconnects, remains down for 2 mins., re-connects, link A-C disconnects, remains down for 6 min., re-connects and so on. As we can see, there is a pattern here. I sense there might be some sort of interference, perhaps between the BH20’s at Site “A”. I cannot confirm if they’re synced or not, by the way.
Has anybody ever seen this problem before? What is the fix? What should the “correct” settings for the 4 Canopy BH20’s be for two side-by-side independent links, like those depicted in the diagram below?
Thanks.
Fernando
There are a lot of questions that need to be answered here.
What frequencies are they connecting on?
Is it or is it not synchronized?
Have you ran a spectrum analysis at any of the sites yet?
Is there any vertical separation on the pole at Site A?
In order to better troubleshoot this you really need these answered.
Self interference.
Install a PacketFlux SyncPipe and SyncSplitter at Site A, make both radios masters, connect Sync to the RJ11 and set the radios to Receive Sync on Timing Port.
Make sure both radios are configured with the same DL%. Also make sure you have at least 50MHz of channel separation. You may also need to physically separate the BH masters on the tower but I would wait until everything else is done.
Thanks pcpolo and Jerry for the replies:
What frequencies are they connecting on?
Is it or is it not synchronized?
Have you ran a spectrum analysis at any of the sites yet?
Is there any vertical separation on the pole at Site A?
As far as I could find out, all of those items were overlooked. I don’t know about the frequencies, but the answer to the other questions is ‘No’.
Install a PacketFlux SyncPipe and SyncSplitter at Site A, make both radios masters, connect Sync to the RJ11 and set the radios to Receive Sync on Timing Port.
Make sure both radios are configured with the same DL%. Also make sure you have at least 50MHz of channel separation. You may also need to physically separate the BH masters on the tower but I would wait until everything else is done.
I forwarded the suggestion to the upper technical management. They’ll handle it with the original installation crew. I’ll be back when new problems arise (it’ll be in April).
Thanks again,
Fernando