Thursday, November 28, 2013

Configuring an EnGenius Technologies Long Range 11n 2.4GHz Wireless Bridge/Access Point (ENH202): Computers & Accessories

A buddy of mine decided he wanted a bridged connection to my home network. With a bit of input from me he settled on the EnGenius Technologies Long Range 11n 2.4GHz Wireless Bridge/Access Point (ENH202) ($90/each for two devices). It took a couple of tries, but we were able to configure a point-to-point bridge connection.

The reason this took a couple of tries is that the EnGenius comes with the worst documentation of any device I've ever seen. It's not the usual problem of limited documentation -- there's lots of documentation. Problem is, it's all incomplete and/or contradictory. Unsurprisingly, so is the firmware for these devices. This feels like its made in China 2013 for China 2013. It doesn't feel cheap though, it feels pretty solid -- made to survive outdoors. Go figure.

Oh! And the first set we ordered both shipped without the inline adapter for the Power Over Ethernet connection. We reordered and got the adapters. Yeah, a mess.

The documentation and hardware confusion has to be at least partly related to feature creep. This device is supposed to connect offices or remote billboards over 1 km point-to-point connection, but it does several different things:

  • Access Point connected to Router/Net
  • Client Bridge remote (IP Based)
  • WDS Access Point
  • WDS Bridge Mode MAC Based Network
We device ships with a 1 page setup page that gives some documentation clues, but most of the documentation is on a mini-CD that requires an old-fashioned spindle drive. We ended up configuring the devices as a WDS MAC based bridge (connection is based on MAC address, not IP address) relying on two documents:

I suspect WDS MAC mode is not the 'safest' way to configure these devices. Not only is it almost undocumented (despite all the documentation), but the link quality lights don't work in WDS mode and the UI is rough and inconsistent. For example, sometimes saving a change restarts the ENH202, other times you have to find the Save/Restart menu item and explicitly save changes, and for password changes, it's not quite clear when and how it saves a change.

If you decide to try MAC based WDS bridge (can include up to 4 devices connecting to each other) the sequence is somethign like this:

  1. Starting from the default IP address, manually assign each device an IP address that will work with their network destination (when configured as Bridge both will we on the same network, for us we used 192.168.0.100 and 192.168.101 with subnet mask 255.255.255.0. (Usual procedures with changing IP of configuring computer, etc).
  2. Name devices so you can tell which is which.
  3. Learn MAC (ethernet) address of each device. Disregard what's printed on a sticker -- it was completely wrong. Use the web config UI.
  4. In the WDS Link Setting Screen enter MAC address of remote device (on each device).
  5. Optional: We set devices to 802.11n only, specify matching channel (band within n range), etc.
  6. Test link.
  7. Add encryption.
  8. Add device password

Given that the link quality lights work in Client Bridge, but not in WDS Bridge mode, and given the poor quality of the WDS Bridge documentation, I suspect this device works better in Client Bridge mode (IP based connection)

Once we had it working the  WDS Link Status screen gave us a receiving signal strength of RSSI dBm -74. Wikipedia put that in context for units of dBm:

  • 80: FM radio 50km range (output)
  • 33: Maximum output from a UMTS/3G mobile phone (Power class 1)
  • 30: Typical RF leakage from a microwave oven
  • 31: Maximum output from a UMTS/3G mobile phone (Power class 4)
  • 15: Wireless LAN transmission power in laptops.
  • 0: Bluetooth standard 1m range (output)
  • -10:  maximum received signal power (−10 to −30 dBm) of wireless network
  • -80 dBM: typical range of wfi received signal power (range is -70 to -90)
  • -127: Typical received signal power from a GPS satellite
  • - 140; Received signal for LTE phone
  • - 192: thermal noise floor 1Hz bandwidth space

So for a WiFi received signal we're not too badly off (our homes are close). We could have boosted power further but so far throughput is limited by my 8-10 mpbps DSL connection.

1 comment:

PII said...

The Author of this specific submission is spot on, correct.

I purchased one of the ENS 202EXT units on Friday and between then and now have looked at no less than 125 videos, read no less than 25 manuals regarding the minute configuration required to set up this unit in a way where it will connect to an existing WISP and bridge to my existing Netgear Router.

The documentation is copious but the detailed examples through which you can effect your specific setup are NON-EXISTENT.

THe expereinces with not knowing if it has done simple things like reset the default password, or recorded your changes for any peculiar setting leads me to believe that the owners of this company DO NOT SPEAK ENGLISH as their native language and therefore are fully unaware of these nuances and how English works.

The manuals suffer from and display this deficiency

Since it is the weekend their Support desk is closed they do not give any service until Monday when I will call and see how IF AT ALL, if this unit can be configured as anticipated.

I have reset it to its default IP no less than 20 times