Maybe a picture is worth a thousand words or a thousand troubles. Recently I was called in to fix a fiber backbone issue and to survey the site and the customer wares. The site survey was more work than fixing the fiber issue itself. It revealed numerous problems, and one photograph I took is shown below.
This campus network wasn't typical of what we find. Instead it had numerous Intermediate Distribution Frames (IDFs) and the network was riddled with hubs, switches and individual retail Wi-Fi devices mixed in with another Wi-Fi system that simply failed to work.
The immediate tasks were to resolve a connectivity issue between buildings using existing fiber and to replace the existing switches. Each end of the fiber terminated in media converters. The older 62.5mm fiber SC ends simply needed conversion using an SC/LC patch cable to connect to new fiber transceivers we installed. The 3-pair fiber cable only used the first pair between the buildings, delivering less than 100Mbps through the media converters that were not power protected or on a UPS.
With the existing network and fiber pair in service, we bonded two un-used pairs using the "aggregation" feature of the new switch with 2.5-Gbps transceivers, and we were able to build a 5-Gbps pipe between the buildings. As shown in the photo, the issues we noted included:
Housekeeping – There is no wire management. Older 25-pair riser cabling is also taking up space on the plywood. Smart Jacks are installed wherever there is space. Power strips are hanging and plugged into other power strips (not shown in photo).
Aerial Cable –The green 25-pair cable exits the building and follows the same aerial path as the fiber to the building next door. The green cable is, in fact, not aerial rated and it's an indoor riser rated cable not suitable for aerial and outdoor use. Weather will impact performance because it is essentially a lightning rod and water will penetrate the outer cable sheath.
OSP Digital Station Protectors – Someone added these modules but didn't properly ground them. These protectors are used for TDM proprietary phones connected to the other building.
ADTRAN Router with Battery Backup – The service provider isn't providing service when the router loses power, and since the backup battery is completely dead the customer complaints were not exaggerated.
UPS –The black UPS is completely dead, and it is connected to the TDM telephone system.
Metro Ethernet Router –This bonds two circuits and is completely unprotected.
The reason we conducted the site survey was to unveil the issues we faced in converging this campus and networking multiple buildings. Then to add to the project, a new building is being constructed, and there is no legal direct patch to run private fiber.
Once the new managed LAN switches (ADTRAN 1544) were programmed and set, we tested the fiber span and implemented a new subnet for the LAN and new VLANs for future use. We removed another router we found, in the process discovering that the telephone service serving the Nortel PBX was lost. The router also supplied another service for drop and insert, and we quickly restored the router to service. Befuddled, we could not obtain dial tone from the provider's span. Fortunately, the secretary knew that for years when users dialed 9 to place outside calls that they expected "dead air" and not a dial tone.
In my prior post, I discussed broader issues that companies face when trying to converge or just obtain reasonable Internet service.
Follow Matt Brunk on Twitter and Google+!
@telecomworx
Matt Brunk on Google+
