XRT86L30
REV. 1.0.1
SINGLE T1/E1/J1 FRAMER/LIU COMBO
14.6
T1 Non-Signaling Frame Format
The Non-Signaling (N) framing format is a simplified version of the T1 super frame. The N-Frame consists of
four frames with two Fs bits and two Ft bits. The Fs bits can be used as a proprietary 4kbps data link
transmission. Signaling is not supported in this framing format.
TABLE 180: NON-SIGNALING FRAMING FORMAT
F-BITS
F
RAME
BIT
TERMINAL
TERMINAL
F
RAMING
F
T
F
RAMING FS
1
2
3
4
0
1
----
X
193
386
579
----
0
----
X
----
14.7
T1 Data Multiplexed Framing Format (T1DM)
T1DM uses a similar framing structure as the SF (D4), such that the Fs and Ft bits on the individual frame
boundaries remain the same. The differentiation between T1DM and SF is within the payload time slots. Time
slot 24 cannot be used for data when configured for T1DM. Time slot 24 is dedicated for a special
synchronization byte as shown in Figure 113. The Y-bit is to carry the status of the Yellow Alarm. The R-bit is
dedicated for a remote signaling bit typically not used. However, the framer allows this bit to carry an HDLC
message. Time slots 1 through 23 are used to carry the seven bit word from each of the 23 DS-0 signals.
FIGURE 113. T1DM FRAME FORMAT
12 T1DM Frames
per Multi-frame
T1DM Frame
Time Slot
Time Slots
2 through 23
Time Slot
24
F
1
Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7
C
1
0
1
1
1
Y
R
0
260
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