PM8611-BIAP PMC [PMC-Sierra, Inc], PM8611-BIAP Datasheet - Page 40

• Manufacturer Part Number: PM8611-BIAP
• Manufacturer: PMC [PMC-Sierra, Inc]

10.1.5
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2010883, Issue 2
ROW #
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T1 Tributary Mapping
Table 8 shows the format for mapping 84 T1s within the SPE octets. The DS0s and framing bits
within each T1 are easily located within this mapping for channelized T1 applications. It is
acceptable for the framing bit to not carry a valid framing bit on the Add Bus since the physical
layer device will provide this information. Unframed T1s use the exact same format for mapping
84 T1s into the SBI except that the T1 tributaries need not align with the frame bit and DS0
locations. The V1,V2 and V4 octets are not used to carry T1 data and are either reserved or used
for control across the interface. When enabled, the V4 octet is the Link Rate octet of Tables 1 and
3. It carries alarm and clock phase information across the SBI bus. The V1 and V2 octets are
unused and should be ignored by devices listening to the SBI bus. The V5 and R octets do not
carry any information and are fixed to a zero value. The V3 octet carries a T1 data octet but only
during rate adjustments as indicated by the V5 indicator signals, IV5 and OV5, and payload
signals, IPL and OPL. The PPSSSSFR octets carry channel associated signaling (CAS) bits and
the T1 framing overhead. The DS0 octets are the 24 DS0 channels making up the T1 link.
The V1,V2,V3 and V4 octets are fixed to the locations shown. All the other octets, shown shaded
for T1#1,1, float within the allocated columns maintaining the same order and moving a
maximum of one octet per 2 KHz multi-frame. The position of the floating T1 is identified via the
V5 Indicator signals, IV5 and OV5, which locate the V5 octet. When the T1 tributary rate is faster
than the SBI nominal T1 tributary rate, the T1 tributary is shifted ahead by one octet which is
compensated by sending an extra octet in the V3 location. When the T1 tributary rate is slower
than the nominal SBI tributary rate the T1 tributary is shifted by one octet which is compensated
by inserting a stuff octet in the octet immediately following the V3 octet and delaying the octet
that was originally in that position.
Table 8 T1 Framing Format
COL #
1-18
Unused
Unused
Unused
Unused
Unused
Unused
Unused
Unused
Unused
Unused
Unused
Unused
Unused
Unused
Unused
T1#1,1
19
V1
DS0#1
DS0#4
DS0#7
DS0#10
DS0#13
DS0#16
DS0#19
DS0#22
V2
DS0#1
DS0#4
DS0#7
DS0#10
DS0#13
T1#2,1-3,28 T1#1,1
20-102
V1
-
-
-
-
-
-
-
-
V2
-
-
-
-
-
103
V5
DS0#2
DS0#5
DS0#8
DS0#11
DS0#14
DS0#17
DS0#20
DS0#23
R
DS0#2
DS0#5
DS0#8
DS0#11
DS0#14
SBSLITE™ Telecom Standard Product Data Sheet
T1#2,1-3,28 T1#1,1
104-186
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
187
PPSSSSFR
DS0#3
DS0#6
DS0#9
DS0#12
DS0#15
DS0#18
DS0#21
DS0#24
PPSSSSFR
DS0#3
DS0#6
DS0#9
DS0#12
DS0#15
T1#2,1-3,28
188-270
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Preliminary
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