I have just changed over a friend's system from VFX Naked DSL Fusion POTS analogue line off a Linksys WAG310G to VFX Asterisk service but am receiving long delays of up to 15 seconds randomly between when the dialled number is sent and the called number rings. This has happened calling XT mobiles, 0800 numbers including the XNET Help Desk, voicemail (082210) and normal local landlines including VFX landlines. I have installed a new Siemens Gigaset A580IP Duo with the same settings as my own Gigaset (except for Username and Password). My own system has been running extremely well for over a year now.
XNET help desk checked on a couple of my calls and advised there was no delay at their end between when Asterisk received the call and actioned the dialled number. My friend said that prior to installing the Gigaset she often experienced long delays, especially when calling mobile phones. Does anyone have any ideas on this? What's causing the delay? Could there be a problem at our local exchange?