Scenario:

Site A has a Merlin Legend (with 400EM card) and Site B has Norstar (with E&M trunk cart). Is there any kind of adapter that I can use to tie the two sites together so that calls can be transferred between sites and extensions called between sites? I know there will be some dial plan changes & translations, I am aware of that. I'm just looking to see if there is any hardware out there than can make use of Site A and Bs broadband connections to tie the two systems together for the above purposes. Please list models if possible.

Thanks.