Recommended equipment for wireless link between two buildings

On 9 Aug 2006 09:53:02 -0700, "Charles Kerekes" wrote in :

Do you need outdoor equipment, or do you have windows with line of sight and without film?

Either way, you'll need (1) wireless access point and (2) wireless client bridge that can support multiple MAC addresses, both with support for WPA, and with external directional antennas on both.

John,

Thanks for the reply. Yes, the equipment will have to be outdoors. So far I am looking at the following:

- Cisco Aironet 1300 Series Outdoor Access Point/Bridge

- D-Link DWL-7700AP Wireless AG Outdoor AP/Bridge

- Proxim Tsunami QuickBridge II

All of the above support WPA and external antennas.

Charlie

On 9 Aug 2006 13:06:31 -0700, "Charles Kerekes" wrote in :

Any of those should work.

Since you are using the Cisco network equipment I would suggext the Cisco 1240 Access points. They can be configures as an access point, bridge or workgroup bridge on either or both of the radios. They have seperate radios for 802.11B/G and 802.11A. The best solution is to use the 802.11A interfaces for the bridging or backhaul and the G for local wireless clients if needed. External antennas would be required as there are no built in antennas on the access points.

A second solution is to use the Proxim 5054 802.11A wireless bridges. These bridges have if you buy the right version a power over ethernet to the radio antenna combo. This allows the unit to be placed outdoors with no cable losses and no need for any addditional antennas. The Proxim bridges can deliver throughput of about 23 mbits per second half duplex. It is more than adequate in most situations for five users. The radio also has a built in peltier cooler and heater so that they can be placed outdoors in all types of weather. I have several in service in areas that exceed 120 in the summer or below 0 in the winter with no trouble.

Charles Kerekes wrote:

On 9 Aug 2006 13:52:23 -0700, "kbloch2001" wrote in :

Figure $1200+ for a pair. Can you say, "OUCH!"

Not much cheaper than Cisco.

The manager is "cost conscious" and there are quality solutions for quite a bit less.

Some times the lowest cost equipment is not the cheapest to operate long term. I have placed many links in place and using cheap equipment usually costs more in the long run.

Consumer quality equipment like dlink, netgear etc is fine for home use. It becomes very expensive when people cannot work because the link is down. If a network is already using the Cisco equipmenet they understand the value of having things work when they are supposed to.

$1,300 for a pair is more like it plus antennas etc will easily make it over $2,000 for a link. the Proxim bridge kit can be found for about $2,000 last I saw at CDW. The Proxim is designed for outdoor use and would offer higher throughput and easier to install as a RF cable is not needed and cable losses are not an issue.

John Navas wrote:

I agree, except for your putdown of D-Link et al, which actually make gear as good or better than what you recommended; e.g.,

• D-Link DWL-7700AP Wireless AG Outdoor AP/Bridge

• ZyXEL ZyAIR B-5000 Outdoor Access Point & Bridge The DWL-7700AP is one of the options being considered by the OP, along with Cisco and Proxim.

On 10 Aug 2006 07:24:46 -0700, "kbloch2001" wrote in :

Thanks for all the advice. One critical point I failed to mention earlier is that we are also using VoIP on a separate/dedicated Cisco network (another area that I'm just now learning). This wireless link will have to carry not only data, but also 5 VoIP phone conversations.

Because of the VoIP requirement, I have been looking more at the Proxim Tsunami QuickBridge II 40 2xT1/E1 Link. This device reserves two T1 channels for VoIP. It claims to be the easiest to configure. If my choice is between Proxim and Cisco, I see the following advantages:

Proxim: Dedicated T1 channels for VoIP, probably simpler to configure than accomplishing the same with QoS on Cisco. The promised simplicity is appealing to me because I am not familiar with these technologies. But, I'm not sure if simplicity is the best long-term choice for this decision.

Cisco: We have other Cisco equipment and are familiar with the interface and configuration. In general, I tend to favor standardization within an organization, giving the Cisco another advantage. My concern is the higher level of perceived complexity to establish this data/VoIP link.

Both will be in the $2000 range for the link, Cisco maybe a little higher--basically equal in price.

I would appreciate additional advice regarding the VoIP component, especially from those who have used the Proxim solution.

Charlie

The Proxim choice may have a dedicated T1 that is used for voice but that is not for VOIP. VOIP uses a ethernet type service and the T1 is a voice type service. A T1 has 24 voice channels that are each 64 kbits wide giving a total of 1.544 mbits per second. If only five channels are used the other bandwidth for the T1 service is unused but still consumed over the air.

For a VOIP type deployment where call quality is very important I would reccomend the Proxim equipment as it is designed for outdoor use with the WORP protocol which is a Proxim name for a polled type protocol versus the standard 802.11a protocol of the cisco units. Being that the subscriber unit gets polled from the base station unit the problem of collisions is greatly reduced or non existant.

Keep in mind that both the cisco and Proxim radios mentioned are half duplex radios. This may cause a problem with VOIP calls at some point in time but ususally the delay is so short that most voip equipment will not have any problems.

For ease of installation and cost versus performance I would still reccomend the Proxim 5054 outdoor units for both subscriber and Base station. A complete kit at CDW is around $2,300 and eliminates the need for coax cable and a seperate antenna. The only thing you may need is either a outdoor rated cat5 cable or you need to run the cable inside a conduit or a UV protected sleeve such as 1/2 flexible tubing used for drip irrigation.

As far as the person who took offence to my comments about dlink etc. My comments stand. they are very suitable for home use but not a good choice in my opinion for a business type environment as they do not have all the management features or reliablity over the long term that more expensive solutions offer. I would not want to put my job on the line by using consumer grade equipment for anything important. We have a wirleess access point setup for guest connections to the internet using a newer linksys access point that needs to be rebooted a few times a week. The device is not desinged for a always on type enviroment. The device replaced a Belkin Pre N router that was even worse. Simply put the consumer grade equipment is not desinged for a long life time.

Charles Kerekes wrote:

kbloch2001,

Two more questions about the Proxim 5054, if you don't mind:

1) I could not find any mention of WPA in the 5054 specs (only WEP). I called Proxim support and he said the WPA is supported. I'm not sure if I should believe the published specs or tech support. Do you know if WPA is supported by this product?

2) If my data and VoIP networks are separate, does that mean I need two sets of wireless links? That seems like the least complex option if we want to maintain isolated networks. If yes, then will two sets of antennas near each other interfere?

I really appreciate your feedback, especially since you seem to have hands-on experience with the Proxim bridge.

Charlie

there is an alternate box which may be useful - the 1310 APs are outdoor unit with an embedded patch antenna - so can be used like the Proxim unit.

these things cost around 450 - 500 UK pounds each + tax ($900 US?)

Note that the Cisco ones can work well with Cisco 7920 IPT wireless phones, and there are recommended settings for this and other VoIP applications.