Re: draft of a core protocol spec

Frank,

I just read your draft that you posted to the IPoRPR list this week. I have a few comments.

jl

Technical:
3: 802.17 does not determine and default to the shortest path. The standard is purposely silent on this. Instead, 802.17 rings determine the topology of the ring, allowing a choice of shortest path, or some other algorithms to be employed.
3: The 802.17 frame format will almost for sure change next week at the next 802.17 plenary meeting.
4.1: The client (host or router) does not set the TTL or frame type. The MAC sets these values.
4.1: ringletID may be selected by the client. But I assume you are stating it this way since this is simple version that doesn't try to do anything fancy. If so, you may want to clarify this statement.
4.3: Do you think it would be useful to have a method of indicating this? If so, do you think we should do so via the MIB, or what?
4.6: The MTU can be changed from the default only via 802.17 negotiation (via the topology discovery protocol). While this could be triggered by an administrative command or by a router advertisement, these are just possibilities, and still just triggers.
5.1: I certainly would prefer a new type code.
8.3: Only partially true. Service could be denied only to other classC (BE) traffic, and only to a limited extent. The fairness algorithm keeps any one station from using more than its fair share of BE bandwidth availability. (And more limitations caused by allocations for classB (AF) and classA (EF) that I'd be happy to explain.)
9: See my comment on 5.1.
10.8: Please update to reference D1.1, October 25.

Editorial:

1: Starting on page 2, the footer lists an expiration date of May 2002 instead of May 2003.
3: Starting in this section, you use "node" and "nodes" whereas 802.17 uses "station" and "stations".
3: Starting in this section, you use "ring" for the purpose that 802.17 uses "ringlet". Note that 802.17 distinguishes between a ring and a ringlet. A ring is comprised of 2 counter rotating ringlets.
3: 802.17 now refers to the ringlets as ringlet0 and ringlet1. Inner and outer are used only in diagrams where ringlet0 is shown as the outer ringlet, transmitting clockwise, and ringlet1 is shown as the inner ringlet, transmitting counterclockwise.
3: Starting in this section, you use "packet" for the purpose that 802.17 uses "frame". Note that 802.17 distinguishes between a packet and a frame. Packet is used for the SDU of higher layers, such as IP, whereas frame is used for the PDU used by 802.17.
3: As of draft 1.1, Packet Type (PT) has changed to Frame Type (FT), and the reserved bit (R) has changed to the parity bit (P), which is used only for fairness frames and reserved for all other frames.
3: RI stands for ringlet identifier.
3: Change "Which the ring" to "Which ringlet".
4.4: Since this always confuses people, you might say in addition or instead that it is the same order as used by Ethernet.