> -----Original Message----- > From: Joe Touch [mailto:to...@isi.edu] > Sent: Wednesday, May 06, 2015 3:42 AM > To: Tom Herbert; Templin, Fred L > Cc: Xuxiaohu; Donald Eastlake; tr...@ietf.org; n...@ietf.org; > int-area@ietf.org; > s...@ietf.org > Subject: Re: [trill] Fwd: Mail regarding draft-ietf-trill-over-ip > > > > On 5/5/2015 12:34 PM, Joe Touch wrote: > >> Or just define a simple version translation as part of encapsulation. > >> > So for IPv8: > >> > > >> > 0x1000->0x0101 on encapsulation > >> > 0x0101->0x1000 on decapsualtion > > And what happens to 0x0101 WHEN it shows up? > > > > You need more patterns than you have because IP is allowed to use any > > of them. > > FWIW, you're essentially arguing for bit-stuffing, i.e., if a pattern you > think will > be common shows up, don't stuff, and if something else shows up, then do. > > That works only if you do true stuffing, e.g.,: > > 0x01** = uncompressed > (might as well add 0x11** and 0x10** to that) > 0x00** = compressed > > But then if 0x0000, 0x0001, 0x0010 or 0x0011 show up, you need to decide > how to represent them - they CANNOT be uncompressed without at least two > more bits somewhere else that indicates they're uncompressed and their value. > > So now your GUE methods are very sensitive to IP version numbers, which IMO > defeats the "G" in the name. Never mind how this complicates hardware when
Agree. As I had mentioned to Tom in private, I do believe the additional capability of GUE (e.g., fragmentation) would be much useful in some network environments. However, since GUE is intended to be a generic UDP encapsulation approach, we'd better design it as generic and future-proof as possible from the beginning, specifically speaking, without being deeply influenced by a particular GUE payload type. If both foo-in-GUE (foo could be NSH, TRILL...) and foo-in-UDP (i.e., a compact version of foo-in-GUE) are needed someday, could you still achieve the same effect as that for IP-in-UDP (as a compact IP-in-GUE) and IP-in-GUE? Best regards, Xiaohu > (not if) other IP versions are used (for whatever reason). > > Joe > > _______________________________________________ Int-area mailing list Int-area@ietf.org https://www.ietf.org/mailman/listinfo/int-area
