14-5
Cisco ONS 15310-CL and Cisco ONS 15310-MA Ethernet Card Software Feature and Configuration Guide R8.5
78-18133-01
Chapter 14 Configuring Resilient Packet Ring on the ML-Series Card
Understanding RPR
Figure 14-3 RPR Frame for ML-Series Card
The RPR framing and header includes a number of fields, including four bytes for source and destination station information and another four bytes for RPR control and quality of service (QoS). Figure 14-4 illustrates the RPR frame format. Table 14-1 defines the most important fields.
Figure 14-4 RPR Frame Fields
134984
Flag Add Control Protocol
0x7E 0x0F 0x00 0x0042
1 byte 1 byte
CRC Flag
0x7F
2-4 bytes 1 byte
FCS
4 bytes
1 byte 2 bytes
RPR Payload
68-1522 bytes
RPR Address RPR Control
4 byte 4 bytes
Ethernet Payload
60-1514 bytes
Preamble SFD
7 byte 1 byte
DA
6 bytes
SA
6 bytes
Ln/Type
6 bytes
Data/Pad
46-1500 bytes
Table 14-1 Definitions of RPR Frame Fields
Destination Station An eight-bit field specifying the MAC address of a specific ML-Series card in the RPR as the destination. It has two well-known addresses, 0xff for Multicast DA-MAC and 0x00 for Unknown DA-MAC.Source Station An eight-bit field specifying the MAC address of a specific ML-Series card in the RPR as the source.
Destination ID Destination Station
Protocol (RPR V1)
Payload (Ethernet Frame)
134982
Source ID Source Station
PRI W TTL
Wrap Station RSVD Type
BD
ED
VD
W
D
S
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0