Outbound call while original inbound caller on hold

[philpandco]

Hi folks

I'm using a SIP-T20P and I'm having a slight problem trying to do the following.

When somebody calls me, and I need to put them on hold, and make an outbound call while the original caller is still on hold, it's forcing me to use Line 2 to do this, which isn't active.

Is there a way of making a second call whilst a first call is on hold, using the same account?

I was able to do this using another brand of phone on the same SIP account, so I know it's supported by the server.

If anybody could help that would be great.

Thanks,

Ben @ Philp & Co