| Business | Phone |
| Atx Telecomm Md Dip 1007 Skidmore Dr, Annapolis 21401 | (410) 626-8150 |
| Calso Communications Inc Annapolis 21401 | (410) 269-5251 |
| Seibert Group 603 Canal Ln, Annapolis 21401 | (410) 349-0717 |
| Silicon Valley Telecomms 230 Dubois Rd, Annapolis 21401 | (410) 897-4856 |
| Synergics Telemetry 191 Main St, Annapolis 21401 | (410) 268-1003 |