Hi All,
The diagram and text below reflect my understanding of the lengthy discussion we had this morning on this topic.
The plan is to propose this as the baseline text for the D05 version of our draft. If this motion is not approved, I would like to continue the discussion on
this reflector. For the sake of time, I would like to have some baseline text in the document which covers the case where we want to concurrently indicate both
timestamp and seqnum.
Thanks,
Richard
1.1
RoE control packet header format (00 0000b)
[///Editor’s note : how do we communicate orderingInfo type??
This subclause documents the first octets in a frame that is common to RoE control packets. Figure 10 illustrates the frame format and its fields. The RoE control packet frame format follows the generic RoE frame format defined in subclause 0 unless stated
otherwise.
Figure 14: RoE control packet common frame format
1.1.1
Version (ver) field
See subclause 4.4.1.
1.1.2
Packet type (pktType) field
The pktType field for a RoE Control Packet shall be set to value 00 0000b (see Table 2).
1.1.3
Flow identifier (flowID) field
The flowID field shall be set to the NIL value (1111 1111b) (see Table 3) unless otherwise specified by a RoE Control Packet
subtype definition. See subclause 4.5.5 for further details regarding the RoE Control Packet subtypes.
1.1.4
Ordering information (orderInfo) field
See subclause 4.4.5. Note that sequence numbers may behave differently between RoE control packets and their associated RoE data packet flows. For example the
seqNumPMax and seqNumPVal can be different for RoE control packets and data packets. The RoE control packet subtype specification shall describe the exact sequence number handling.
1.1.5
Length field
See subclause 4.4.4.
1.1.6
Subtype field (subtype)
The subtype field is size of 8 bits and defines additional control packet types. This document reserves Control Packet
subtype values listed in Table 5.
Table 5 – RoE Control Packet subtype values
|
Binary value |
Function |
Description |
|
00 0000b |
Reserved |
|
|
00 0001b |
Ctrl_AxC words |
Ctrl_AxC data. |
|
00 0010b |
VSD |
Vendor specific control packet |
|
00 0011b |
Timing packet |
A packet containing both TimeStamp and Seqnum |
|
00 0100b –
11 1111b |
Reserved |
Control packet subtypes available for use between two RoE endpoints. |
1.1.7
Payload field
See subclause 4.4.6. for generic definition. The content depends on the control packet subtype.
1.1.8
Ctrl_AxC (pktType 000000b subtype 00 0001b)
[///Editor’s note : describe/reference payload for Ctrl_AxC packets
1.1.8.1
VSD packet (pktType 000000b subtype 00 0010b)
[///Editor’s note : describe/reference payload for VSD packets
1.1.8.2
Timing packet
(pktType 000000b subtype 00 0011b)
The timing packet is a control packet which contains both the
seqnum and timestamp field. The flowID field indicates which
flowID the orderingInfo is associated with.
Figure 15 Timing packet format