Central Office Switches

  • Lucent No. 5 ESS
  • Northern Telecom DMS 250
  • Northern Telecom DMS 500
  • Alcatel E10B
  • Harris 20/20

  • Digital Protocols

  • T1 E&M
  • T1 ISDN Primary Rate
  • E1 R2MFC
  • E1 Decadic
  • E1 System Signaling 7

  • Analog Protocols

  • Loop Start
  • E & M
  • Ground Start
  • DID (reverse voltage)

  • Serial Protocols

  • SMDI
  • Eastern Identifier
  • TNPP
  • Northern Telecom DMS 100
  • Northern Telecom DMS 50
  • Siemens EWSD
  • Erricson AXE-10
  • Metaswitch VP3500



  • T1 Loop Start
  • T1 SS7
  • E1 R1MFC
  • E1 ISDN Primary Rate