[acs] CMIS Generating UPN Problem

[pbad]

We have completed the CMIS 14.1 upgrade on Friday 16th May. After the upgrade office staff have been unable to generate UPN. The following error message appears when trying to generate a UPN "all available serial numbers have been used". I have contacted Link2ict and they have said that there are large gaps between the numbers that are being allocated.

 

Has anybody had a problem like this before? Everytime we do an upgrade we have had slight problems that we have managed to resolve, but nothing like this.

[Banjo]

"all available serial numbers have been used"

 

From memory your Facility license key allows a certain number of concurrent users - its sounds as if have more users than the license code will allow.

[SkywOrca]

UPNs are generated by the system using a strict set of rules defined by the DfE. It uses various pieces of information to create the UPN including DfE country code, school code, a cohort identifier and a three digit index unique to the pupil which starts at 001 and can run up to 999. This information is then passed into another algorithm that generates the letter code which acts as a verification code to ensure that the UPN has been generated correctly and should be unique (flipping a single digit in the number will invalidate the checksum letter).

 

Facility keeps track of which UPN's have been issued by inspecting the current highest order serial number for your combination of county code, school code and cohort number, then adds one and generates the number from there. What this means is that it is possible to generate UPNs that skip over index numbers from this sequence, and this is what has happened in your case. You already have a pupil that has used the 999 serial number for this cohort, so the system will no longer be able to generate new UPNs for you. Since there is no way of knowing if one of the skipped serial numbers has been used in an official return we cannot simply regenerate numbers from those missing blocks, therefore until the start of the next academic year you will need to obtain UPNs from the LA as they can generate ones that are known to be unused. The problem should be resolved in September, but you might need to double check that the method you are using to generate UPNs is the most efficient and doesn't lead to these skipped serial numbers

 

Edit:

Please note, this is not an issue with the 14.1 release as these skipped serial numbers are spread throughout the year.

Edited May 22, 2014 by SkywOrca

[pbad]

What's the best way to generate UPNs?

[SkywOrca]

Given that we're so close to the end of the academic year, you're probably best just calling the LA for a new UPN each time you need one. From September onwards your UPN serials will reset so you'll be able to generate them again as normal. The only other alternatives would involve removing UPNs from pupils with high order serial numbers in order to clear some room in the series, but this would involve getting any UPNs that had now gone up the chain or out to other schools changed to new values to maintain consistency - certainly more work at this stage than getting the LA to issue you with UPNs from the pot that they know are unused.