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Posted

I am looking to connect a boarding house back to the main building over 187.5m of rugby field and driveway.

There is a clear line of sight without trees or steep elevation and I have been recommended a 1GB Duplex laser system to avoid digging up the rugby field and drive.

 

Has anybody got a laser system in place who can reassure me that this is a robust type of connection?

 

Thanks.

Posted (edited)
I would go for a wireless point to point link.

 

I have heard that lasers really don't like snow or rain, wireless is effected by it but not as badly.

 

Yup this - I've heard goo things about these too $1500 each - about £2.5k

 

airFiber | Ubiquiti Networks, Inc.

 

 

You just have to buy via reseller.

Edited by glennda
Posted
I know of a college near to me that has four laser links installed and swear by them. Once properly aligned and the proper precautions taken (such as stopping birds sitting in front of them) they say they are better than wireless.
Posted

We have a laser link installed between our 2 sites - around 220m. We went for an MRV 1gbit system and its brilliant. The only time its been down is during very heavy snow(Nov/Dec 2010 I think) - the school had already been closed for half a day at that point so I wasn't too worried.

 

we also have a radio backup in place that kicks in during heavy snow/fog - I disconnected the wireless during the snow last time so that I could see when it was actually down otherwise I'd probably only have seen 1 missed ping while it switched over.

 

Fog wise I really wouldn't worry about it on a 188m link - I pulled a load of data from our local weather station via wunderground while researching it all and worked out that we only had around 2-5hrs of less than 200m visibility in our area per year, most of which was out of school hours or lasted less than an hour.

 

I treat our link as if it were a fiber connection, if staff on the other end are having problems the last thing I consider is the laser link being down.

 

We used AIT - Home - Data Centre and Networking IT Technical Services - AIT-PG for our installation and ongoing maintenance, we pay nearly £2k/year for a yearly maintenance visit(re-alighment) and emergency support. If a head breaks they replace it and cover the cost of access equipment. For us the maintenance visit alone pretty much covers the cost as each visit involves 2 large cherry pickers and 2 of their engineers.

  • Thanks 1
Posted

I inherited a Laserbit LB-ODU-AC-1/230/TP when I joined here in 2009. To be fair, at the time it was about the only bit of kit in the entire school that worked so I took it for granted. To this day, it's never missed a packet, never failed for fog, snow, torrential rain, plague of frogs etc and it's performance is excellent, just like having a 100mb wired connection. The distance is about 250m between the two receivers.

 

Andrew

 

PS - I am well aware that as soon as I hit send, it will catch fire, cut the roof off a passing bus and bring down a plane full of orphans on to a nearby hospital....

Posted

We have a pair of Ruckus ZF7731s connecting an off-site building and it works a treat - it's only 100M away, and we get the full 190Mbps (which is apparently possible up to 1 mile). The pair of them, +3 years support / warranty was less than £2k ex VAT.

 

Outdoor 802.11n Bridge AP (ZoneFlex 7731) | Ruckus Wireless

 

Edit: as it's wireless, there are a lot less Line of Sight issues, it hasn't gone down once, and is powered by PoE at both ends :).

 

Simon

Posted

What speeds are actually needed for this link?

 

Whilst a Gigabit is all well and good if the boarders are all just going to use it to access your Internet connection do you need Gigabit?

We get 200Mbps from 5Ghz wireless bridges nowadays and they are not expensive at all and very reliable.

In real world testing we have loaded them up at 200mbps for 48hrs and never lost a packet.

 

Ubi 5Ghz Nanos will work both in the unlicensed and licensed 5Ghz band for £50 a year you can get an Ofcom License and put you backhaul on a channel that's well away from the potential noise from .ac enabled systems when they begin to kick off.

 

If you have safe access and can self install your look at around £300 for all of the bits, a decent Sky or Antenna installer can do the installation if you don't have the right H&S qualifications or kit for working at heights.

They even do a rubber sucker mount if you want to sit them in a window.

Posted

Initially I am only looking for the system to be used for boarders access to the internet but there are some offices in the same building which I will look to have computer access in the future.

I think I would feel most comfortable knowing the system I put in had room to expand than putting in 100mb and finding it inadequate shortly after.

 

Self install can be a problem for me as I am the only IT person at the school here. Maintenance seem to know when I need help in the hols and all go on holiday at the same time!

 

I am pleased to hear there are folks with working and stable laser links already in place :)

I will mention both the laser and wireless links in my budget meeting later but in honesty I am sure they will just tell me to go for the cheaper option >_<

 

Thanks

Posted

Only one extra thing to watch out for on the laser option, that's the sun!

I came across one site that had regular issues with their laser installation.

After examining the switch logs extensively we realised that dependent on the cloud cover at certain times of the year and specific times of day the sun was so low it killed one end of the link until the sun fell out of alignment.

So be aware of an East West laser link as one or the other end can be wiped out early or late in the day.

I think they minimised it to a few minutes network blackout everyday by fitting extended shields but were never able to completely fix it and relied on the wifi backup link to cover them.

Posted
Thanks to everyone for their help and sharing experiences - sadly this project was canned in the budget meeting but I will propose again next year.

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