On 04/28/2011 01:06 PM, Joss Giffard wrote: > Hi, > > I recently updated our asterisk system to astlinux 0.7.7 whilst moving > to a new SIP trunk provider. Everything seems to be up and running > correctly apart from the fact that very occasionally each of the VoIP > phones will receive an incoming call from 'asterisk' that once answered > is simply silence... I was wondering if anyone else has experienced > anything similar or has any idea what would be causing this (or indeed > how to cure it). The phones themselves are all Grandstream GXP2000s.
Looks like SIP scanning/spamming/toll fraud attack. You could tweak your Asterisk configuration to not allow any other un-authenticated inbound calls than from your SIP trunk provider and/or add some further security controls to prevent such things. Here is a report from someone who had a similar experience: http://www.fonality.com/trixbox/forums/trixbox-forums/open-discussion/blank-call-caller-id-asterisk There are also some ideas on how to block such calls. Some are good, some may not make sense to everyone. Regards, Ingmar ------------------------------------------------------------------------------ WhatsUp Gold - Download Free Network Management Software The most intuitive, comprehensive, and cost-effective network management toolset available today. Delivers lowest initial acquisition cost and overall TCO of any competing solution. http://p.sf.net/sfu/whatsupgold-sd _______________________________________________ Astlinux-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/astlinux-users Donations to support AstLinux are graciously accepted via PayPal to [email protected].
