Datasheet
____________________________________________________ DS34T101, DS34T102, DS34T104, DS34T108
63 of 366
Figure 10-22. UDP/IP-Specific OAM Packet Format
Table 10-18. UDP/IP-Specific OAM Payload Fields
Field Description
L, R, M Identical to those of the bundle being tested
Length OAM message packet length (in bytes)
OAM Sequence Number Uniquely identifies the message. Its value is unrelated to the sequence number of the TDM
data packets for the bundle in question. It is incremented in query messages, and replicated
without change in replies.
OAM Msg Type Indicates the function of the message. At present, the following are defined:
0: one way connectivity query message
8: one way connectivity reply message
OAM Msg Code Information related to the message; its interpretation depends on the message type.
For OAM Msg Type=0 (connectivity query) messages, the following codes are defined:
0: Validate connection
1: Do not validate connection
For OAM Msg Type=8 (connectivity reply) messages, the available codes are:
0: Acknowledge valid query
1: Invalid query (configuration mismatch)
Service Specific
Information
Can be used to exchange configuration information between gateways. If not used, it must
contain zero. Its interpretation depends on the payload type. At present, the following is defined
for AAL1 payloads:
Bits 16–23: Number of timeslots being transported, e.g. 24 for full T1
Bits 24–31: Number of 48-byte AAL1 SAR PDUs per packet, e.g. 8 when packing 8 AAL1 SAR
PDUs per packet
Source Bundle Identifier The bundle identifier used for TDM-over-Packet traffic from the source to the destination.
Destination Bundle
Identifier
The bundle identifier used for TDM-over-Packet traffic from the destination to source.
Source Transmit
Timestamp
The time the PSN-bound gateway transmitted the query message. This field and the following
fields only appear if delay is being measured. The resolution is configurable to 100 s or 1 s.
Destination Receive
Timestamp
The time the destination gateway received the query message.
Destination Transmit
Timestamp
The time the destination gateway transmitted the reply message.
For more details about OAM Signaling, see Section 10.6.17.
10.6.2
Typical Application
In the application below (Figure 10-23), the device is embedded in a TDMoIP gateway to achieve TDM connectivity
over a PSN. The TDM-over-Packet packet formats for both IP and MPLS are shown in Figure 10-24 an
d
Figure 10-25,
respectively.