if your schedule permits, would like people to chime in and describe some of the mistakes and cockups you have seen when out in the field, either correcting bad installations or site surveys.
Recently experienced a scenario that demonstrates the cost of not checking your work.
I was approached by a company who needed help resolving a major problem with their recent WLAN installation. The company was in the 3rd party warehousing business with sites across Europe and had chosen one of their UK sites to pilot a migration from narrowband to 802.11 as their existing infrastructure was EOL and no longer supported. They had commissioned a professional site survey and had the infrastructure installed, but the they could not achive network logon anywhere on the site. Both the surveyors and the installers were adamant their work was correct and the client was now desperate.
I obtained a copy of the survey and, as the UK wireless community is fairly incestuous and I knew the engineers, spoke to one of the guys who conducted the survey. The survey had been done professionally and met customer needs. I also spoke to the installers who were adament is was a customer network issue and not their installation.
On arrival onsite I verified the surveys coverage and that there was no connectivity. I reconfigured the WEP key on 1 AP and achieved immediate association. After distributing the WEP key to all APs the customer could now connect across the site. A phone call to the installers revealed that the installation engineer had configured 1 AP then distributed the config. The logical explanation was that he had made a typo in entering the WEP key on the original config, and distributed the typo. What he didn't do was verify his work.
Whilst onsite I also discovered that several APs were set at 50mw transmit and had 6dbi directional patch antennas. The surveyors had specified using cable to attenuate to ETSI regulations but the installers had not used the cable. 9 APs exceeded ETSI EIRP regulations.
I now have a very nice contract to oversee the rollout across Europe. The surveyors have been contracted to cover the other sites. The installers have been fired.
A costly lesson for that installation company who really do need to get their staff certified.