Multitech RouteFinder MTASR2-203, User Manual, Page: 23 / 90

Chapter 3 - Software Loading and Configuration
MTASR2-203 23
24. Click OK when you are satisfied with your selections.
25. The Default T1 Parameters dialog box is displayed.
Set the T1 Framing Format to match that of your T1 Service provider.
The D4 Framing Format is a 193-bit frame format that uses the 193rd-bit for framing and signaling
information. The D4 Framing Format uses 12 frames.
The Extended SuperFrame (ESF) Framing Format uses 24 frames and provides CRC error detection
and 4Khz Facility Data Link (FDL).
26. Set the T1 Line Coding to match that of your T1 Service provider.
The Alternate Mark Inversion (AMI) Line Coding is a bipolar coding scheme in which successive ones
alternate in polarity to prevent a BiPolar Violation (BPV). A BPV occurs when two consecutive ones
are the same polarity.
The B8ZS Line Coding technique is used to satisfy the ones density requirements of the T1 carrier
facilities while also allowing clear channel data. Since the system timing is recovered from the pulse
width of the ones, it is important to ensure that there is an adequate proportion of ones in the data
stream. If the data stream contains more than 8 consecutive zeros - a condition that could disrupt
system timing - B8ZS substitutes a predetermined pattern for the zeroes. This substitution
intentionally causes a BPV to occur, alerting the unit on the receiving end that a substitution has
taken place.
27. Set the T1 Line Type and Length for either a short haul line type or long haul line type.
The long haul line type is CSU (0db) or DSX-1 (0-133ft) option which is also the default. CSU allows
the DSX-1 signal to be transmitted up to 6000 feet at Line Build Out (LBO) options of 7.5db, 15db, or
22.5db.
The DSX-1 is a short haul line type often referred to as “Cross-connect” within the telco central office.
The DSX-1 is available in 5 ranges up to 655 feet.
28. Set the T1 Channel Allocations for the number of channels assigned by the local T1 Service provider.
If a full T1 service is provided (e.g., 24 channels), then use the default and click OK to continue.
If a fractional T1 service is provided, then click on each channel that is not in service and then click
OK to continue.