tcpdump mailing list archives
Re: Request for link-layer header type (XRA)
From: Bruno Verstuyft <bruno.verstuyft () gmail com>
Date: Mon, 4 Dec 2017 10:02:04 +0100
2017-12-01 18:25 GMT+01:00 Guy Harris <guy () alum mit edu>:
On Dec 1, 2017, at 3:34 AM, Bruno Verstuyft <bruno.verstuyft () gmail com> wrote:Type 75 is still labeled as "ODMA REQ" rather than "OFDMA REQ". Also,itsays "ODMA REQ (75): as described by section 7.4.8 "REQ Messages" of the DOCSIS 3.1 Physical Layer Specification. This is the "REQ message inMAC"in figure 7-11 (56 bits).", but I don't see a figure numbered 7-11 intheDOCSIS 3.1 Physical Layer Specification (CM-SP-PHYv3.1-I12-171026) - is this from another version of that document?Apparently, the figure had number 7-11 in version I11 of the PHY spec,andis figure number 14 in version I12 of the spec. I updated the number to14,to reflect the number in the more recent spec. I also added references to the DOCSIS MULPI and PHY specification version numbers, to avoidconfusionin the future.Figure 14 shows how it's generated, but the surrounding text doesn't say what the content is; it just says "REQ messages are short messages used by the CM to request transmission opportunities from the CMTS. These messages have a different structure than the data messages: they are always 56 bits long, they always use QPSK modulation, do not apply any FEC and are block interleaved." What do the 56 bits in question contain? Are they one of the -REQ messages described in the DOCSIS 3.1 MAC and Upper Layer Protocols Interface Specification, or are they something else? These are the Queue-depth Based Request Frames described in the MULPI
spec. Changed the reference from the section in the PHY spec to the section in the MULPI spec. _______________________________________________ tcpdump-workers mailing list tcpdump-workers () lists tcpdump org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
Current thread:
- Re: Request for link-layer header type (XRA), (continued)
- Re: Request for link-layer header type (XRA) Guy Harris (Nov 14)
- Message not available
- Re: Request for link-layer header type (XRA) Bruno Verstuyft (Nov 16)
- Re: Request for link-layer header type (XRA) Guy Harris (Nov 16)
- Re: Request for link-layer header type (XRA) Guy Harris (Nov 16)
- Re: Request for link-layer header type (XRA) Bruno Verstuyft (Nov 21)
- Re: Request for link-layer header type (XRA) Guy Harris (Nov 22)
- Re: Request for link-layer header type (XRA) Bruno Verstuyft (Dec 01)
- Re: Request for link-layer header type (XRA) Guy Harris (Dec 01)
- Re: Request for link-layer header type (XRA) Bruno Verstuyft (Dec 01)
- Re: Request for link-layer header type (XRA) Guy Harris (Dec 01)
- Re: Request for link-layer header type (XRA) Bruno Verstuyft (Dec 04)
- Re: Request for link-layer header type (XRA) Guy Harris (Dec 04)
- Re: Request for link-layer header type (XRA) Bruno Verstuyft (Dec 05)
- Re: Request for link-layer header type (XRA) Bruno Verstuyft (Dec 11)
- Re: Request for link-layer header type (XRA) Guy Harris (Dec 11)
- Re: Request for link-layer header type (XRA) Bruno Verstuyft (Dec 12)