Asterisk SIP extension

Hi, i’m using asterisk I have a SIP extension set up to receive external incoming calls with Voipfone as the VoIP provider. I noticed when i get an incoming call on the SIP extension, if i put the caller on hold he is played the Asterisk on hold music rather than the VoIPfone music. Is there any way of changing the settings to resolve this. This suggests Asterisk is in the signalling path, anyway to change so Asterisk is not in the path.

I was thinking if Asterisk could proxy the INVITE and other SIP messages to the extension this would work, is this possible?