Re: [Ila] Questions about SRv6 mobile user-plane
"Sri Gundavelli (sgundave)" <[email protected]> Fri, 26 Jan 2018 19:27:57 +0000
| Newsgroups | gmane.ietf.mip6 |
|---|---|
| Message-ID | <D690C049.2A1F56%[email protected]> |
--===============2442871634124654912== Content-Language: en-US Content-Type: multipart/alternative; boundary="_000_D690C0492A1F56sgundaveciscocom_" --_000_D690C0492A1F56sgundaveciscocom_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Jeff, Out focus is on anchor management. W.r.t traffic steering, Satoru-san's wor= k is the basis and we will leverage that. The below questions are specific = to that work. We should discuss these points. Regards Sri From: Jeff Tantsura <[email protected]<mailto:[email protected]= >> Date: Friday, January 26, 2018 at 10:36 AM To: Sri Gundavelli <[email protected]<mailto:[email protected]>> Cc: Tom Herbert <[email protected]<mailto:[email protected]>>, "dmm@ietf.= org<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>, "[email protected]= g<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [Ila] [DMM] Questions about SRv6 mobile user-plane Hi Sri, My observations are very close to Tom's. Is new draft going to address questions asked or there will be follow up? Thanks! Regards, Jeff On Jan 26, 2018, at 09:19, Sri Gundavelli (sgundave) <[email protected]<ma= ilto:[email protected]>> wrote: Hi Tom: Marco and myself are planning to publish another proposal on anchor-less mo= bility (leveraging SRv6). That may be of interest to you from ILA point of = view. We will post the draft in one or two weeks. Regards Sri From: dmm <[email protected]<mailto:[email protected]>> on behalf of = Tom Herbert <[email protected]<mailto:[email protected]>> Date: Friday, January 26, 2018 at 9:13 AM To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>= , "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: [DMM] Questions about SRv6 mobile user-plane Hello, I am working on a comparison between ILA and SRv6 for the mobile user-plane= . I have some questions/comments about SRv6 and particularly on the example= use cases that were depicted in the slides that were presented in IETF100: https://datatracker.ietf.org/meeting/100/materials/slides-100-dmm-srv6-for-= mobile-user-plane/ - It's clear from the depicted use cases that extension header insertion is= being done by intermediate nodes, but extension header insertion is curren= tly prohibited by RFC8200. There was an I-D posted on 6man to allow this fo= r SR, but that was met with pushback. Is there going to be followup to reso= lve this? - For the uplink use cases, this seems to be more like using SR to source r= oute to an egress router. In other words, it's not strictly related to mobi= lity. Is there some connection to mobility that I'm missing? - The size or number of SR headers in the uplink cases seems to be larger t= han necessary (IMO minimizing these is important since each additional sid = is ~1% overhead of standard MTU). In this first scenario sid[1]=3DA2::1 and= DA=3DA2::1-- this seems to be redundant information. Also this depicts a s= econd SR being inserted, but the first one should no longer be relevant. Wh= y not just discard the first one and save the overhead? In the second scena= rio, DA is changing from A2::1 to A3::1, but AFAICT that was not done per t= he SR processing. What is the operation that happened here? (it's actaully = looks like an ILA transfomation). - Considering the points above, could this have been done in the following = manner to minimize overhead? A1 creates one SRH with one sid and makes DA= =3DA2. A2 makes DA=3DA3. At A3 SR is processed, DA is restored to Internet = address, and EH is removed. - For downlink this does see to be relevant to mobility. But I have the sam= e question, wouldn't it be less overhead to only use one SRH and one sid? i= .e. A3 creates an SRH with just one sid that is the S:: (identifier in iden= tifier/locator speak) and set DA to A2, and then A2 sets DA to A1, A1 resto= res original packet for delivery. - One possible typo. In the last use case slide SA=3DS:: and DA=3DD::, I be= lieve these should be swapped? Thanks, Tom _______________________________________________ ila mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/ila --_000_D690C0492A1F56sgundaveciscocom_ Content-Type: text/html; charset="iso-8859-1" Content-ID: <[email protected]> Content-Transfer-Encoding: quoted-printable <html> <head> <meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Diso-8859-= 1"> </head> <body style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; line-break:= after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Cali= bri, sans-serif;"> <div>Hi Jeff,</div> <div><br> </div> <div>Out focus is on anchor management. W.r.t traffic steering, Satoru-san&= #8217;s work is the basis and we will leverage that. The below questions ar= e specific to that work. We should discuss these points.</div> <div><br> </div> <div>Regards</div> <div>Sri</div> <div><br> </div> <div><br> </div> <span id=3D"OLK_SRC_BODY_SECTION"> <div style=3D"font-family:Calibri; font-size:11pt; text-align:left; color:b= lack; BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM:= 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid;= BORDER-RIGHT: medium none; PADDING-TOP: 3pt"> <span style=3D"font-weight:bold">From: </span>Jeff Tantsura <<a href=3D"= mailto:[email protected]">[email protected]</a>><br> <span style=3D"font-weight:bold">Date: </span>Friday, January 26, 2018 at 1= 0:36 AM<br> <span style=3D"font-weight:bold">To: </span>Sri Gundavelli <<a href=3D"m= ailto:[email protected]">[email protected]</a>><br> <span style=3D"font-weight:bold">Cc: </span>Tom Herbert <<a href=3D"mail= to:[email protected]">[email protected]</a>>, "<a href=3D"mailto:= [email protected]">[email protected]</a>" <<a href=3D"mailto:[email protected]">dm= [email protected]</a>>, "<a href=3D"mailto:[email protected]">[email protected]</a>&= quot; <<a href=3D"mailto:[email protected]">[email protected]</a>><br> <span style=3D"font-weight:bold">Subject: </span>Re: [Ila] [DMM] Questions = about SRv6 mobile user-plane<br> </div> <div><br> </div> <div> <div dir=3D"auto">Hi Sri, <div><br> </div> <div>My observations are very close to Tom’s.</div> <div>Is new draft going to address questions asked or there will be follow = up?</div> <div><br> </div> <div>Thanks!<br> <br> <div id=3D"AppleMailSignature">Regards, <div>Jeff</div> </div> <div><br> On Jan 26, 2018, at 09:19, Sri Gundavelli (sgundave) <<a href=3D"mailto:= [email protected]">[email protected]</a>> wrote:<br> <br> </div> <blockquote type=3D"cite"> <div> <div>Hi Tom:</div> <div><br> </div> <div>Marco and myself are planning to publish another proposal on anchor-le= ss mobility (leveraging SRv6). That may be of interest to you from ILA poin= t of view. We will post the draft in one or two weeks.</div> <div><br> </div> <div><br> </div> <div>Regards</div> <div>Sri</div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <span id=3D"OLK_SRC_BODY_SECTION"> <div style=3D"font-family:Calibri; font-size:11pt; text-align:left; color:b= lack; BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM:= 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid;= BORDER-RIGHT: medium none; PADDING-TOP: 3pt"> <span style=3D"font-weight:bold">From: </span>dmm <<a href=3D"mailto:dmm= [email protected]">[email protected]</a>> on behalf of Tom Herbert &l= t;<a href=3D"mailto:[email protected]">[email protected]</a>><br> <span style=3D"font-weight:bold">Date: </span>Friday, January 26, 2018 at 9= :13 AM<br> <span style=3D"font-weight:bold">To: </span>"<a href=3D"mailto:dmm@iet= f.org">[email protected]</a>" <<a href=3D"mailto:[email protected]">dmm@ietf.= org</a>>, "<a href=3D"mailto:[email protected]">[email protected]</a>" &= lt;<a href=3D"mailto:[email protected]">[email protected]</a>><br> <span style=3D"font-weight:bold">Subject: </span>[DMM] Questions about SRv6= mobile user-plane<br> </div> <div><br> </div> <div> <div> <div dir=3D"ltr"> <div>Hello,</div> <div><br> </div> <div>I am working on a comparison between ILA and SRv6 for the mobile user-= plane. I have some questions/comments about SRv6 and particularly on the ex= ample use cases that were depicted in the slides that were presented in IET= F100:</div> <div><br> </div> <a href=3D"https://datatracker.ietf.org/meeting/100/materials/slides-100-dm= m-srv6-for-mobile-user-plane/">https://datatracker.ietf.org/meeting/100/mat= erials/slides-100-dmm-srv6-for-mobile-user-plane/</a><br> <div><br> </div> <div>- It's clear from the depicted use cases that extension header inserti= on is being done by intermediate nodes, but extension header insertion is c= urrently prohibited by RFC8200. There was an I-D posted on 6man to allow th= is for SR, but that was met with pushback. Is there going to be followup to resolve this?</div> <div><br> </div> <div>- For the uplink use cases, this seems to be more like using SR to sou= rce route to an egress router. In other words, it's not strictly related to= mobility. Is there some connection to mobility that I'm missing?</div> <div><br> </div> <div>- The size or number of SR headers in the uplink cases seems to be lar= ger than necessary (IMO minimizing these is important since each additional= sid is ~1% overhead of standard MTU). In this first scenario sid[1]=3DA2::= 1 and DA=3DA2::1-- this seems to be redundant information. Also this depicts a second SR being inserted, but t= he first one should no longer be relevant. Why not just discard the first o= ne and save the overhead? In the second scenario, DA is changing from A2::1= to A3::1, but AFAICT that was not done per the SR processing. What is the operation that happened here? (it'= s actaully looks like an ILA transfomation).</div> <div><br> </div> <div>- Considering the points above, could this have been done in the follo= wing manner to minimize overhead? A1 creates one SRH with one sid and makes= DA=3DA2. A2 makes DA=3DA3. At A3 SR is processed, DA is restored to Intern= et address, and EH is removed.</div> <div><br> </div> <div>- For downlink this does see to be relevant to mobility. But I have th= e same question, wouldn't it be less overhead to only use one SRH and one s= id? i.e. A3 creates an SRH with just one sid that is the S:: (identifier in= identifier/locator speak) and set DA to A2, and then A2 sets DA to A1, A1 restores original packet for deliv= ery.</div> <div><br> </div> <div>- One possible typo. In the last use case slide SA=3DS:: and DA=3DD::,= I believe these should be swapped?</div> <div><br> </div> <div>Thanks,</div> <div>Tom</div> <div><br> </div> <div> </div> <div><br> </div> <div><br> </div> </div> </div> </div> </span></div> </blockquote> <blockquote type=3D"cite"> <div><span>_______________________________________________</span><br> <span>ila mailing list</span><br> <span><a href=3D"mailto:[email protected]">[email protected]</a></span><br> <span><a href=3D"https://www.ietf.org/mailman/listinfo/ila">https://www.iet= f.org/mailman/listinfo/ila</a></span><br> </div> </blockquote> </div> </div> </div> </span> </body> </html> --_000_D690C0492A1F56sgundaveciscocom_-- --===============2442871634124654912== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ dmm mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmm --===============2442871634124654912==--