If you are placing your SA-100 Service (Conference) Appliance in a DMZ, you have quite a few ports that need to be opened up to your internal Shoretel network.  These are the ports listed in the Shoretel install guide - but listed in order instead of a non-sequential table:

UDP:

53

67

111

123

162

5004

5440

5441

5442

5443

5445

5446

5450

5451

5458

5463

5466

5500-5600

10000-10550

TCP:

20

21

25

53

80

111

443

4306

4308

4309

5222

5432

5449

5450

5457

5466

5469

5500-5600