Dial through fraud suggestions

[Oxosaysno]

Hi All,

Just thought i would let you know about a problem - DTA (dial through fraud) that has become a major problem for us specifically to OXO customers. I want to share this with you so that you will not have the same pitfalls and hardship we have had to go through. I am based in the UK so it may differ country to country.

The DDI range is polled by war diallers to get access to voicemail then digits entered to find mailboxes with default/generic passwords in order to divert extensions remotely.

Alcatel made a specific TC with regards to this - TC1143

We have followed this and also made our own recommendations as follows:

- modified barring levels to include #, *, op con numbers (e.g. 150 155 118)
- set barring category to level 1 on voicemail ports (internal only on our systems) and set traffic sharing link to 15 also set traffic sharing matrix so subscriber link 15 has no access to trunks.
- on R310/055.001, R410/056.001, R510/035.001 and R610/033.001+ and R710/022.001+ systems set PerAssAlwd (other label) to 00 to diable personal assistant.
- disabled the guest barring category from the account code table - mainly applies for R1-2 systems as Personal assistant will use this if the voicemail ports are blocked.
- On R610/033.001+ and R710/022.001+ systems set VMUMaxTry (debug label) to 03. this limits number of voicemail password attempts to 3 before locking it down.
- last of all things to check with customer:
is external divert needed on extensions
is joining required specifically for incoming to outgoing
check barring level of extensions
enforce policies of passwords being regularly changed and secure by PBX owners

Hope this helps some of you to pre-empt this.

[jan.abbeloos]

hi there,
Change PersAssAlwd(in Other Labels)up to version 7 from 01 to 00.This problem should have been solved from version 7 onwards.
Hope this will help.
Jan