MT92210 Zarlink Semiconductor, MT92210 Datasheet - Page 92

• Manufacturer Part Number: MT92210
• Description: 1023 Channel Voice Over ip (VoIP) Processor
• Manufacturer: Zarlink Semiconductor

92
RTP connections can generate Event Reports when special events or errors occur. These Event Reports indicate
all UDP and RTP packaging errors encounters while parsing the packet. This includes fatal errors like UDP
Checksum Error, RTP Version Mismatch and Bad packet Length 1 (which indicates that the RTP headers were too
long for the packet length). It also reports structure Initialization, RTP packet Loss (detected through the sequence
numbers) and Payload Type Report, which is set when the Report bit associated to the RX RTP Channel Structure
is set. This structure reports the current packet's sequence number and the sequence number of the previous
received packet (when RTP is enabled), as well as the Payload Type and Marker bit for RTP packets or the UDP
Payload Length for UDP-only packets. The current Local Bus Timestamp is also written in the structure.
These errors are documented in the following figure that gives the format of these events:
I
L
R
BL1
RVM
UCE
RX RTP
Connection
Structure Address
M & Payload Type
Field
+C
+A
+E
Figure 48 - RX Disassembly Event Report Queue - RTP Connection Report
+0
+2
+4
+6
+8
b15
M
Set at reception of the first packet on the RX Connection Structure.
Loss of one or many RTP packets detected because the sequence number fields of two
consecutive packets were not incremental. The Previous and Current Sequence
Numbers will indicate number of lost packets.
This bit is set when the R bit is set in the RX Channel Structure Split Entry (as taken for
the packet).
Bad Packet Length 1. When set, a packet has been received with insufficient bytes to
contain an RTP header. It will be discarded entirely.
RTP Version Mismatch. When ‘1’, this means that a packet was received with RTP
version not equal to 2.
UDP Checksum Error. When set, a packet has been received with an incorrect UDP
checksum.
Base address of the RX RTP Connection Structure that generated this report structure.
Theses two fields contain the value of the Marker bit and Payload Type of the RTP
packet that caused this error structure to be generated.
b14
b13
Payload Type [6:0]
b12
I
RX RTP Connection Base Address [20:5]
Table 31 - Fields and Description
Previous RTP Sequence Number [15:0]
b11
L
This RTP Sequence Number [15:0]
Local Bus Time Stamp [31:16]
b10
Local Bus Time Stamp [15:0]
Zarlink Semiconductor Inc.
b9
R
BL1
b8
b7
Description
RVM UCE
UDP Payload Length [7:0]
b6
b5
b4
b3
0
b2
0
b1
0
b0
1