MT92220 Zarlink Semiconductor, MT92220 Datasheet - Page 106

• Manufacturer Part Number: MT92220
• Description: 1023 Channel Voice Over IP/AAL2 Processor
• Manufacturer: Zarlink Semiconductor

106
9.2
The AAL2 treatment is similar to the RTP treatment: in AAL2, the UUI and Length will be concatenated and used to
index in a Generic UUI/LI table, which in a similar way will determine the type of the packet. The Generic UUI/LI
Table Base in the RX AAL2 Connection Structure points to this table. Since the UUI and LI together are 11 bits, the
Generic UUI/LI Table has 2048 entries, contrarily to the 256 in RTP. However, in AAL2, the indexing is fixed per
profile, and consequently a few tables (for the handful of profiles the chip might be supporting at any one time) will
be sufficient for all AAL2 connections.
The format of the RX AAL2 Connection Structure is the following:
AAL2 Treatment
+1A
+16
+18
+56
+10
+12
+14
+54
+A
+C
+E
+0
+2
+4
+6
+8
b 15
0
0
b14
R
R
b13
Figure 57 - RX AAL2 Connection Structure
Type
Type
b12
RX AAL2 Channel 15 Structure Address [20:5]
RX AAL2 Channel 0 Structure Address [20:5]
Generic UUI/LI Table Base [20:10]
b11
Received Packet Count [15:0]
Received Octet Count [31:16]
Zarlink Semiconductor Inc.
b10
Received Octet Count [15:0]
b9
b8
b7
b6
b5
b4
b3
xxPCM Info
xxPCM Info
b2
0
0
b1
b0
0