hardware questions -best way to bridge

[Kevinh]

I need to get a t1 connection (may be a T3 in future) to 2 different building locations. I do no have line of site between them. I do have line of site from aonther building to all 3. Here is what I would like to do.


Builidng A sends 1.5 meg T1 signal to builidng B.

Building B sends T1 signal to both building C and D

The distance between A and B is about 500 feet.

The distance between B and C is about 2000 feet

The distance between B and D is about 2500 feet

I have looked at the Cisco 1300 and the Proxim 2454-R

Can I get some suggestions on the best way to accomplish this? Is there other hardware that would be recommended for this task.

Thnaks in advance

Kevin

[M/Q]

Hello Kevin,

I always have questions first.

1. Have you totally eliminated a wired solution? Wired is better in a business environment bar none.
2. What is your budget?
3. What kind of throughput are you expecting across each link?
4. Have you completed a site survey to see if there were any existing RF sources that might create interference? It will determine which band you need to use. (ie 802.11a or 802.11g)
5. What is the sensitivity of the data moving across these links? Privacy issues may require VPNs

I am very happy as you seem to be one that I do not have to persuade to use business class devices. The 1300 is a great device, it could be used throughout this network. Others will want to promote the Proxim device and it is a good piece of equipment as well. But, come on Cisco rules. 8-)

If you are determined to use wireless, I would like to understand what the RF topology of the links is before committing to a solid design. I would set it up with 802.11a, especially if you are in an urban setting. If you are not or you have budget constraints then the 1300 would work just fine. If you need to use 802.11a then the Cisco 1400 would be ideal. I would like to wait until you answer the questions before getting too granular in the actual topology.

[golfnut]

Proxim 802.11a bridges rule M/Q (I've played with both, real world)...

It's easily expandable, easier to configure, has AES encryption, detailed QoS configurations, and affordable.

Okay, I'm done, sorry to butt-in -:)

Greg

[M/Q]

Hey Greg,

You are more than welcome to butt in. I was hoping that you would, (ie my remark). The more information presented the better the decision will be.

[Kevinh]

I agree that a wired solution is aways preferable. I amy be able to get from building a to b. But from A to C or D is nearly impossible at this point. Sometime in the past a parking lot was paved over the only cable access location between A and C-D. Unfortunately no one has any as built plans to tell me where in the parking lot that access location is and I have tried several company's to do a locate on it. We are at near sea level so when a signal is placed on the phone line-cable tv etc the signal just gets spread over the complete area. My ultimate goal is to provide "high speed internet access" in 40 Condo units and not in the condos that are not part of our resort program. Currently we have only 1 T1 available to our entire 400 room resort. With some heavy business users here the bandwidth crawls. We are hoping to add a second T1 when we install the condo's but convincing the financial people of 6-7 hundred dollars a month for a free service that is not always used is tough in itself. As for budget I have allocated 6 grand for this part. Once in the condo building we will use a local dsl sled solution to get to the individual rooms just as we do in the hotel. Here is the link to that product (Pretty neat and clean solution) http://www.teledex.com/index.cfm?page=LP_1&crid=79. So overal bandwidth at best would never be over 1.5 meg. Reliability is an issue thus the reason for the 1300's I need that part to be rock solid. Other than other small linksys type access points within the building there is no other signals around us that I am aware of. But I have not used anything to confirm that. Any recomendations on that? If 802.11a reduces the chances of interference I am all for it. We do have guests that use VPN and we need to make sure that NAT transfers correctly. How about this for a support nightmare- 400 people all from different comapnies with different configurations all coming to you and wanting to get on the internet. 90% of them do not have any local permissions to make any changes without their IT staff and when they can't connect it is the resorts fault for not being able to help them.

[M/Q]

Great information. My thoughts are:

1. If at all possible use a wired link from A to B. Really try hard as it removes a rather significant bottleneck and one less area of possible interference.
2. Use B as the Point of a Point to MultiPoint topology. Where are the locations of C and D compared to B if you had a degree circle located at B. If C and D are less that 100 degrees apart with B being the vertex, you can use a good directional sector antenna at B and even tighter direction antennas at C and D.
3. Use Cisco or Proxim and 802.11a for these wireless links. You will not regret that decision at all.
4. VPNs and NAT are not a problem related to the wireless portion of the network design. That occurs at the perimeter or where you separate the internal network from the public network. It is relatively easy to isolate the public network and remove any hands one by the business.
5. Complete a rather sophisticated site survey before doing anything else, it is imperative to learn if you have any unknowns or RF issues that you will have to deal with.

[Kevinh]

Buildings C and D are about 60-70 degrees apart from B. Would you still recommend the Cisco 1300? Ruling out A-B connection for wired then I would need a total of 3 bridges and 3 antennas. Can you recommend an antenna? I would like to mount the bridges in the buildings with the antennas located outside. I know that adding antenna cables lower the db. If I go less than 50 feet will I be OK. Can you give me an estimate on the RF survey? If you can guess an hourly rate so I know when I find someone it is reasonable. Around here, $150.00 hr for any tech fees is about average with rates as high as $250.00 hr if they can get it. I am located in Fort Myers FL and most of the techs come from Tampa or Miami.

[M/Q]

That angle separation is good, it will require only one directional antenna at B. Are you saying you can get a wired connection to B? If so then yes, you only need three devices.

A bit confused as the 1300 is an outdoor device and will last forever there. The 1300 even has an internal antenna model. I was hoping it would have enough gain but it appears that if you are hoping for 802.11g throughput, then you will need approximately 20dBi gain on each antenna. If 802.11b is sufficient then the 1300 with an internal antenna would work just fine. Keep the device near the antenna and run PoE, it is the best way.

Check out these two links.

http://www.cisco.com/en/US/products/ps5861/products_data_sheet09186a00802252e1.html

http://www.cisco.com/en/US/products/ps5861/products_data_sheet09186a008022b11b.html

I am not that well versed as to full time tech rates. I am a fulltime Field Engineer for Orange Business Services so my side job rates are less. Also, the forum rules are such that this subject is not something discussed. PM and email connections are better suited for that.

[DjBlaze]

Proxim 802.11a bridges rule M/Q (I've played with both, real world)...

It's easily expandable, easier to configure, has AES encryption, detailed QoS configurations, and affordable.

Greg

Hi Greg,
So you are saying that with the Proxim bridges, you are able to configure AES as the encryption method over the bridge link? If so, I guess that answers my question about whether or not the bridge protocol supports anything above WEP. After speaking to a Netgear representative, they mentioned that NONE of their products support anything higher than WEP over a bridge link. Any idea why such a big network company would not increase the strength of their bridge algorithm?

[golfnut]

Because bridging with an access point is a secondary function...

Greg