Specifications

Chapter 6 TR-08 Option
6-3
♦ FXS-ID Loop Start and Ground Start channel units with CLASS service support,
including Distinctive Ringing and Caller ID (5ESS only)
♦ Battery Reversal FXS LS with CLASS service support or Dial Pulse Origination
(DPO) (5ESS only)
♦ FXO LS and GS channel units (5ESS only)
♦ 4-Wire E&M Types I, II, IV, and V (5ESS only)
♦ Dial Pulse Termination (DPT) Wink Start, Immediate Start, or 2 Wire, one-way
Direct Inward Dial (DID--5ESS only)
• “US Grade A” telephone line quality:
♦ Three Mile analog loop range, automatic line impedance matching and full V.34
modem support
♦ 85Vac/20Hz ringing voltage with all-channel simultaneous ringing power
♦ Fuseless overvoltage and overcurrent safety protection
♦ Two second Calling Party Disconnect (CPD) eliminates “hung” lines
SUMMARY OF TR-08 MODIFICATIONS
As previously mentioned, TR-08 is simply another T1 channel unit framing protocol, such as D4
or ESF. As such, it simply decodes the T1 signal coming into the channel bank into three
components: the Pulse Code Modulation (PCM) stream, the T1 A/B signalling bits and the TR-08
Data Link (this is the TR-08 equivalent of the ESF facility data link). FXS loop start and ground
start for telephone equipment connections are provided with the SPOTS (Special POTS) 12
channel analog card as specified in TR-08 under Single Party Ringing (SPR) and Universal
Voice Grade (UVG) interfaces respectively. All channel card switches and LEDs on the rear
panel of the Access Bank I function identically to the Access Bank I in D4 or ESF framing
modes.