Toshiba DK14 Installation And Maintenance Manual page 326

T1
Slot Assignments
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ESF provides a more enhanced method of error checking that SF; however, the Channel
Service Unit (CSU) must be compatible with ESF and may cost more than a SF only CSU.
ESF circuits have the additional power of Cyclic Redundancy Checking (CRC), which allows
end-to-end monitoring of T1 circuit performance. ESF, T1 performance monitoring normally
requires that a person be specially trained for this function. SF and ESF Frame format is
adequate for DK Voice (and modem type data) T1/DS-1 transmission.
7. Run Programs *41-3 and -4: These programs allow the RDTU Transmit and Receive (Volume)
level to be adjusted by changing the RDTU built-in digital PAD value between +6 decibels
(dB) and –15 dB. Transmit and Receive levels are individually adjustable on each RDTU (all
channels will have the same level). Toshiba recommends using the initialized levels (Receive
–3 dB/Transmit –6 dB) upon initial installation. Adjust the RDTU digital PAD as required
while testing each RDTU T1 channel.
8. Run Program *42 Series—T1 Span Timing Reference Assignments
Timing references for T1 RDTU PCBs are made with the Program *42 series. The RDTU (T1)
timing (or synchronization) program options determine how the DK system digital voice
transmission path (time-switch) is synchronized with the far end digital system transmission
path. For proper T1 operation, the equipment at each end of a T1 span line must be
synchronized.
The DK time-switch is synchronized (as slave) to the T1 span equipment on the other end of
the T1 line by the RDTU PCB designated as the Primary Reference in Program *42-1. When a
RDTU is connected to a Telco or Long Distance Provider T1 span line, the RDTU in the
8-4
LED 02 (Wink/Immediate): This assignment is for RDDU, REMU, and PEMU lines only;
it does not apply to RDTU Tie or DID lines. Use Program *41-2 to assign RDTU lines for
wink or immediate start.
LED 03: Toshiba recommends turning this LED On (initialized state) for all RDTU DID
lines to enable incoming DID calls to camp-on busy stations. This is also necessary to
allow more than one DID line to ring into a station simultaneously. LED03 does not apply
to RDTU Tie lines.
LED 04: For RDTU Tie lines, LED04 is normally Off to enable dial tone to be received
from the far end Tie line when calling DK stations. For DID lines LED04 is normally On
so RDTU DID lines do not send dial tone to the CO Run *41-1: Use this program to assign
the RDTU (T1) Line Coding method (B8ZS or AMI) and signal Framing format (SF or
ESF). Contact the account representative of the company that is providing the T1 span line
(Local Central Office or Long Distance Provider) to determine which line Coding and
Frame format will be used.
Line Coding: The DK RDTU supports T1/DS-1 transmission of Voice and Analog Data
(using modems) using Alternate Mark Inversion (AMI) with Zero Code Suppression
(ZCS) or Bipolar Eight Zero Substitution (B8ZS) line coding. B8ZS provides clear
channel capability, which allows frame information bits to carry any combination of ones
and zeros—a feature needed for T1/DS-1 transmission of digital DATA (DK does not
support transmission of digital DATA over RDTU T1/DS-1 at this time).
As of this writing, most Telcos provide AMI line coding which is adequate for DK RDTU
voice transmission; however, B8ZS may be required by some long distance providers,
college campus private networks, or customer premise end to end T1 connections. AMI
and B8ZS are adequate for DK Voice T1/DS-1 transmission.
Framing: As of this writing, D3/D4 Superframe (SF), or Type I and Extended Superframe
(ESF), or Type II T1/DS-1 is offered by most all local Telcos and Long Distance
Providers. Normally the local Telco will provide SF, which is adequate for DK voice (and
modem type data) transmission. Long distance providers may offer either SF or ESF.
Strata DK I&M 5/00