Subject: Re: [edu-team] IDR Tutorial for IETF 70

From: Geoff Huston <[email-masked]>
Date: Fri, 12 Oct 2007 14:50:18 +1000

Margaret

I've thought about this some more, and I've come to the conclusion that 
I am not in a position to undertake a major realignment of the material 
in order to concentrate on a meaningful presentation about the 
operational, business, structural and research aspects of interdomain 
routing within the constraints of the time available and within the 
constraints of the audience's familiarity with routing concepts.

I really don't feel that what you are asking for here is realistic 
within the scope of the presentation time, and I must admit to some 
considerable personal doubt that what you are asking for is even capable 
of being presented in a style and format that might be useful to an IETF 
audience. On reflection I have the view that this is not a case of even 
a slim chance of pulling it off - from my perspective its a case of how 
badly it would fail.

Sorry, but from my perspective your expectations here are just simply 
not attuned to what I am confident of being able to deliver in this 
space. So rather than embarking on a major struggle with material for 
the next month to try and prepare material that would align to what you 
are proposing, with a pretty confident expectation of being unable to 
meet the goals you've outlined, it would be best if I simply let you 
know now that your proposed realignment of the tutorial would not work 
for me. I am of course quite happy for the edu team to find someone else 
who would be more confident of being able to prepare material along the 
lines you are wanting here.

regartd,

Geoff

Margaret Wasserman wrote:
> 
> Thanks, Geoff.
> 
> I realize that we're asking a lot, and we trust you to do the best you 
> can.  Although this may be a difficult task, you are, IMO, the most 
> likely person to be able to pull it off.
> 
> One way to think about our comments is that people who have already read 
> a bunch about IETF routing protocols (because there are books and the 
> RFCs out there) still don't really understand what the operations folks 
> mean when they talk about issues in the routing system, because we don't 
> really know that terminology.  I've had multiple smart folks sit through 
> talks on the route table growth in the DFZ and then lean over to me and 
> ask me if I know what the DFZ is, for example.  Many of us don't really 
> know if you are talking about routes on a single router, the union of 
> all DFZ routes, the average number of routes per router or what...  Most 
> of us don't really understand how peering works.  And some people 
> (including me) don't understand what it would mean to put a level of 
> indirection (such as LISP or other tiered routing schemes) somewhere in 
> the Internet (not at the enterprise or DFZ boundary), because we don't 
> understand what interesting levels exist between an enterprise and the 
> DFZ, if any.
> 
> Given the amount of activity in this area in the IETF, including plenary 
> discussions, there seem to be a lot of people who would like to 
> understand this area better.  If there are any good references on this 
> subject, it would also be good to include a list of them in your slide 
> deck...  but I fear that most of this stuff isn't really written down.
> 
> Margaret
> 
> 
> On Sep 27, 2007, at 6:00 PM, Geoff Huston wrote:
> 
>> Hmmm - what you both appear to want out of a couple of hours causes my 
>> brain to hurt. I suppose that from my perspectives such topics as:
>>
>> what is the DFZ and why is it interesting
>> who peers with whom at what level
>> what BGP filters are used
>> what controls exist
>> what can go wrong
>> what are incompatible policies and where do they exist
>> who can you discover incompatible policies
>> how is money done
>>
>> are all topics that can either be treated quickly, superficially and 
>> poorly or topics that take ages to get into and assume a massive 
>> amount of familiarity with routing that you probably know the answers 
>> already.
>>
>> Having said that you are making a Big Ask here, I must admit that the 
>> room in Chicago surprised me - many of the folk there knew all about 
>> BGP the protocol and were asking for what you are asking
>>
>> So let me think about this and see what I can come up with
>>
>>  Geoff
>>
>> Radia Perlman wrote:
>>> Yes, I strongly agree with what Margaret said. In addition, it might 
>>> be nice to cover the
>>> concept of incompatible policies with BGP, and whether such things 
>>> occur in the wild, and if
>>> not, how they are avoided. And to repeat some of what she said in 
>>> different words...what
>>> kinds of issues are people trying to solve with policies (e.g., I 
>>> want to connect to A so A's
>>> customers can talk to my customers, and want to connect to B so B's 
>>> customers can talk
>>> directly to my customers, but I don't want to let A and B use me as a 
>>> through path)? (and
>>> actually, that is about the only example people give -- can you give 
>>> others?)
>>> Also, how is money done? In other words, is there incentive to be a 
>>> through carrier from A to B
>>> because you get paid more money? Or is everything a flat rate so you 
>>> are motivated to do
>>> as little work as possible? Are the charging policies flat rate (if 
>>> they are) because the protocols
>>> don't do sufficient accounting, or the accounting isn't trusted?
>>> Radia
>>> Margaret Wasserman wrote:
>>>>
>>>> Hi Geoff,
>>>>
>>>> Thanks for presenting the IDR Tutorial at IETF 69.  As always, you 
>>>> did an excellent job of preparing and presenting your session.
>>>>
>>>> However, the EDU Team discussed your tutorial and the feedback we 
>>>> received, and we have some thoughts about how to update the tutorial 
>>>> so that it will be even more useful to the IETF community.
>>>>
>>>> What you presented was an excellent BGP tutorial, but you didn't 
>>>> present much information that couldn't be gleaned from reading 
>>>> RFCs.  We know that you have a lot of knowledge about how IDR 
>>>> routing actually works in the wild -- What is the DFZ and why is it 
>>>> interesting?  Who peers with whom at what levels? What types of BGP 
>>>> filters do they use in which directions?  What controls are in place 
>>>> to prevent random BGP routes from hitting the DFZ?  What types of 
>>>> things can (and do) go wrong with the current system?  etc...
>>>>
>>>> So, we'd be interested in seeing more of an introduction to the 
>>>> Internet IDR routing system than just an intro to BGP...
>>>>
>>>> Other members of the EDU Team may want to chime in here with their 
>>>> suggestions, as well.
>>>>
>>>> Would you be willing to update the tutorial along these lines and 
>>>> give it again at IETF 70?
>>>>
>>>> Margaret
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> edu-team mailing list
>>>> [email-masked]
>>>> https://www1.ietf.org/mailman/listinfo/edu-team
> 
> 

_______________________________________________
edu-team mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/edu-team

---

From: Thomas Narten <[email-masked]>
Date: Fri, 12 Oct 2007 10:44:52 -0400

Looking at the original thread more carefully, I have to express some
sympathy for Geoff's reluctance. I've also been involved in many
conversations on routing, and the breadth of issues involved, and the
range of background many IETF people have makes it quite a challenge.

Stepping back, I have to ask, what exactly is the purpose of such a
tutorial? What are attendees expected to take back from such a
session?

Some of the topics that have been mentioned might even be better done
in a roundtable fashion and/or with Q&A. A lot depends on the what the
listener knows and what background they have. And that is quite a
range.

Thomas

---

From: Brian E Carpenter <[email-masked]>
Date: Sat, 13 Oct 2007 10:09:12 +1300

> range of background many IETF people have makes it quite a challenge.

Indeed. Having recently had to teach basic BGP4, I thought about
what if anything to say about the business and policy issues, and
concluded that it is indeed very hard to express in anything like
a precise and neutral manner. I have some sympathy with Geoff's
difficulty.

> tutorial? What are attendees expected to take back from such a

I saw it as understanding the wider context. When you look at the
mechanics of BGP4, communities, AS numbers and so in, it's very
hard to appreciate the subtle effects they have on deployment
and traffic flows. Therefore, it's hard to appreciate the effects
that changes in routing and addressing can have (e.g. the
interactions between mobility solutions and BGP4). I think that's
why the topic fits the EDU mission.

> listener knows and what background they have. And that is quite a

Indeed, which adds to the difficulty. But that sounds more like a
session at a regular conference than at the IETF.

Back to drawing board?

     Brian

---

From: Margaret Wasserman <[email-masked]>
Date: Tue, 16 Oct 2007 08:56:58 -0400

Hi Geoff,

Thanks for letting us know early what you can and can't do for IETF  
70.  I was hopeful that we could get a tutorial that would make it  
easier for people in the IETF to track ongoing discussions about DFZ  
route table growth, etc.  But, I admit that I don't know what that  
would entail.  I will accept your (and Brian's and Thomas') belief  
that this can't be done in a two hour slot.

Even if we could find someone else who would agree to teach the  
material I had in mind, I'd be skeptical at this point that they  
could do a good job, given the thoughts of you and others who should  
know what is involved much better than I do.  I certainly don't think  
it make sense to change horses at this point and try to find someone  
else to do an IDR tutorial in Vancouver.

Many people did seem to be happy with the BGP-oriented tutorial you  
gave in Chicago.  Would you be willing to do that tutorial (with any  
updates you think are necessary based on the previous run) again in  
Vancouver?

Thanks,
Margaret

On Oct 12, 2007, at 12:50 AM, Geoff Huston wrote:

> Margaret
>
> I've thought about this some more, and I've come to the conclusion  
> that I am not in a position to undertake a major realignment of the  
> material in order to concentrate on a meaningful presentation about  
> the operational, business, structural and research aspects of  
> interdomain routing within the constraints of the time available  
> and within the constraints of the audience's familiarity with  
> routing concepts.
>
> considerable personal doubt that what you are asking for is even  
> capable of being presented in a style and format that might be  
> useful to an IETF audience. On reflection I have the view that this  
> is not a case of even a slim chance of pulling it off - from my  
> perspective its a case of how badly it would fail.
>
> Sorry, but from my perspective your expectations here are just  
> simply not attuned to what I am confident of being able to deliver  
> in this space. So rather than embarking on a major struggle with  
> material for the next month to try and prepare material that would  
> align to what you are proposing, with a pretty confident  
> expectation of being unable to meet the goals you've outlined, it  
> would be best if I simply let you know now that your proposed  
> realignment of the tutorial would not work for me. I am of course  
> quite happy for the edu team to find someone else who would be more  
> confident of being able to prepare material along the lines you are  
> wanting here.
>
> regartd,
>
>
> Geoff
>
>
>
>
>
>
>> I realize that we're asking a lot, and we trust you to do the best  
>> you can.  Although this may be a difficult task, you are, IMO, the  
>> most likely person to be able to pull it off.
>> One way to think about our comments is that people who have  
>> already read a bunch about IETF routing protocols (because there  
>> are books and the RFCs out there) still don't really understand  
>> what the operations folks mean when they talk about issues in the  
>> routing system, because we don't really know that terminology.   
>> I've had multiple smart folks sit through talks on the route table  
>> growth in the DFZ and then lean over to me and ask me if I know  
>> what the DFZ is, for example.  Many of us don't really know if you  
>> are talking about routes on a single router, the union of all DFZ  
>> routes, the average number of routes per router or what...  Most  
>> (including me) don't understand what it would mean to put a level  
>> of indirection (such as LISP or other tiered routing schemes)  
>> somewhere in the Internet (not at the enterprise or DFZ boundary),  
>> because we don't understand what interesting levels exist between  
>> an enterprise and the DFZ, if any.
>> Given the amount of activity in this area in the IETF, including  
>> plenary discussions, there seem to be a lot of people who would  
>> like to understand this area better.  If there are any good  
>> references on this subject, it would also be good to include a  
>> list of them in your slide deck...  but I fear that most of this  
>> stuff isn't really written down.
>> Margaret
>>> Hmmm - what you both appear to want out of a couple of hours  
>>> causes my brain to hurt. I suppose that from my perspectives such  
>>> topics as:
>>>
>>> are all topics that can either be treated quickly, superficially  
>>> and poorly or topics that take ages to get into and assume a  
>>> massive amount of familiarity with routing that you probably know  
>>> the answers already.
>>>
>>> Having said that you are making a Big Ask here, I must admit that  
>>> the room in Chicago surprised me - many of the folk there knew  
>>> all about BGP the protocol and were asking for what you are asking
>>>
>>>> Yes, I strongly agree with what Margaret said. In addition, it  
>>>> might be nice to cover the
>>>> concept of incompatible policies with BGP, and whether such  
>>>> things occur in the wild, and if
>>>> not, how they are avoided. And to repeat some of what she said  
>>>> in different words...what
>>>> kinds of issues are people trying to solve with policies (e.g.,  
>>>> I want to connect to A so A's
>>>> customers can talk to my customers, and want to connect to B so  
>>>> B's customers can talk
>>>> directly to my customers, but I don't want to let A and B use me  
>>>> as a through path)? (and
>>>> actually, that is about the only example people give -- can you  
>>>> give others?)
>>>> Also, how is money done? In other words, is there incentive to  
>>>> be a through carrier from A to B
>>>> because you get paid more money? Or is everything a flat rate so  
>>>> you are motivated to do
>>>> as little work as possible? Are the charging policies flat rate  
>>>> (if they are) because the protocols
>>>>> Thanks for presenting the IDR Tutorial at IETF 69.  As always,  
>>>>> you did an excellent job of preparing and presenting your session.
>>>>>
>>>>> However, the EDU Team discussed your tutorial and the feedback  
>>>>> we received, and we have some thoughts about how to update the  
>>>>> tutorial so that it will be even more useful to the IETF  
>>>>> community.
>>>>>
>>>>> What you presented was an excellent BGP tutorial, but you  
>>>>> didn't present much information that couldn't be gleaned from  
>>>>> reading RFCs.  We know that you have a lot of knowledge about  
>>>>> how IDR routing actually works in the wild -- What is the DFZ  
>>>>> and why is it interesting?  Who peers with whom at what levels?  
>>>>> What types of BGP filters do they use in which directions?   
>>>>> What controls are in place to prevent random BGP routes from  
>>>>> hitting the DFZ?  What types of things can (and do) go wrong  
>>>>> with the current system?  etc...
>>>>>
>>>>> Other members of the EDU Team may want to chime in here with  
>>>>> their suggestions, as well.
>>>>>
>>>>> Would you be willing to update the tutorial along these lines  
>>>>> and give it again at IETF 70?
>>>>>
>>>>> Margaret
>>>>>
>>>>>
>>>>>
>>>>>

---

From: Geoff Huston <[email-masked]>
Date: Tue, 16 Oct 2007 23:11:45 +1000

Yes, I would be happy to do that tutorial again and I will update the 
material based on the experience of the previous run of tis material in 
Chicago

regards,

    Geoff

Margaret Wasserman wrote:
> 
> Hi Geoff,
> 
> Thanks for letting us know early what you can and can't do for IETF 70.  
> I was hopeful that we could get a tutorial that would make it easier for 
> people in the IETF to track ongoing discussions about DFZ route table 
> growth, etc.  But, I admit that I don't know what that would entail.  I 
> will accept your (and Brian's and Thomas') belief that this can't be 
> done in a two hour slot.
> 
> Even if we could find someone else who would agree to teach the material 
> I had in mind, I'd be skeptical at this point that they could do a good 
> job, given the thoughts of you and others who should know what is 
> involved much better than I do.  I certainly don't think it make sense 
> to change horses at this point and try to find someone else to do an IDR 
> tutorial in Vancouver.
> 
> Many people did seem to be happy with the BGP-oriented tutorial you gave 
> in Chicago.  Would you be willing to do that tutorial (with any updates 
> you think are necessary based on the previous run) again in Vancouver?
> 
> Thanks,
> Margaret
> 
>> interdomain routing within the constraints of the time available and 
>> within the constraints of the audience's familiarity with routing 
>> concepts.
>>
>> capable of being presented in a style and format that might be useful 
>> to an IETF audience. On reflection I have the view that this is not a 
>> case of even a slim chance of pulling it off - from my perspective its 
>> a case of how badly it would fail.
>>
>> the next month to try and prepare material that would align to what 
>> you are proposing, with a pretty confident expectation of being unable 
>> to meet the goals you've outlined, it would be best if I simply let 
>> you know now that your proposed realignment of the tutorial would not 
>> work for me. I am of course quite happy for the edu team to find 
>> someone else who would be more confident of being able to prepare 
>> material along the lines you are wanting here.
>>
>> regartd,
>>
>>
>> Geoff
>>
>>
>>
>>
>>
>>
>>> One way to think about our comments is that people who have already 
>>> read a bunch about IETF routing protocols (because there are books 
>>> and the RFCs out there) still don't really understand what the 
>>> operations folks mean when they talk about issues in the routing 
>>> system, because we don't really know that terminology.  I've had 
>>> multiple smart folks sit through talks on the route table growth in 
>>> the DFZ and then lean over to me and ask me if I know what the DFZ 
>>> is, for example.  Many of us don't really know if you are talking 
>>> about routes on a single router, the union of all DFZ routes, the 
>>> average number of routes per router or what...  Most of us don't 
>>> really understand how peering works.  And some people (including me) 
>>> don't understand what it would mean to put a level of indirection 
>>> (such as LISP or other tiered routing schemes) somewhere in the 
>>> Internet (not at the enterprise or DFZ boundary), because we don't 
>>> understand what interesting levels exist between an enterprise and 
>>> the DFZ, if any.
>>> plenary discussions, there seem to be a lot of people who would like 
>>> to understand this area better.  If there are any good references on 
>>> this subject, it would also be good to include a list of them in your 
>>> slide deck...  but I fear that most of this stuff isn't really 
>>> written down.
>>> Margaret
>>>> Hmmm - what you both appear to want out of a couple of hours causes 
>>>> my brain to hurt. I suppose that from my perspectives such topics as:
>>>>
>>>> amount of familiarity with routing that you probably know the 
>>>> answers already.
>>>>
>>>> the room in Chicago surprised me - many of the folk there knew all 
>>>> about BGP the protocol and were asking for what you are asking
>>>>
>>>>> directly to my customers, but I don't want to let A and B use me as 
>>>>> a through path)? (and
>>>>>> received, and we have some thoughts about how to update the 
>>>>>> tutorial so that it will be even more useful to the IETF community.
>>>>>>
>>>>>> routing actually works in the wild -- What is the DFZ and why is 
>>>>>> it interesting?  Who peers with whom at what levels? What types of 
>>>>>> BGP filters do they use in which directions?  What controls are in 
>>>>>> place to prevent random BGP routes from hitting the DFZ?  What 
>>>>>> types of things can (and do) go wrong with the current system?  
>>>>>> etc...
>>>>>>

---

From: Margaret Wasserman <[email-masked]>
Date: Tue, 16 Oct 2007 09:38:40 -0400

Thanks, Geoff!

Margaret

On Oct 16, 2007, at 9:11 AM, Geoff Huston wrote:

> Yes, I would be happy to do that tutorial again and I will update  
> the material based on the experience of the previous run of tis  
> material in Chicago
>
>
> regards,
>
>    Geoff
>
>> Thanks for letting us know early what you can and can't do for  
>> IETF 70.  I was hopeful that we could get a tutorial that would  
>> make it easier for people in the IETF to track ongoing discussions  
>> about DFZ route table growth, etc.  But, I admit that I don't know  
>> what that would entail.  I will accept your (and Brian's and  
>> Thomas') belief that this can't be done in a two hour slot.
>> could do a good job, given the thoughts of you and others who  
>> should know what is involved much better than I do.  I certainly  
>> don't think it make sense to change horses at this point and try  
>> to find someone else to do an IDR tutorial in Vancouver.
>> Many people did seem to be happy with the BGP-oriented tutorial  
>> you gave in Chicago.  Would you be willing to do that tutorial  
>> (with any updates you think are necessary based on the previous  
>> run) again in Vancouver?
>> Thanks,
>> Margaret
>>> I've thought about this some more, and I've come to the  
>>> conclusion that I am not in a position to undertake a major  
>>> realignment of the material in order to concentrate on a  
>>> meaningful presentation about the operational, business,  
>>> structural and research aspects of interdomain routing within the  
>>> constraints of the time available and within the constraints of  
>>> the audience's familiarity with routing concepts.
>>>
>>> I really don't feel that what you are asking for here is  
>>> realistic within the scope of the presentation time, and I must  
>>> admit to some considerable personal doubt that what you are  
>>> asking for is even capable of being presented in a style and  
>>> format that might be useful to an IETF audience. On reflection I  
>>> have the view that this is not a case of even a slim chance of  
>>> pulling it off - from my perspective its a case of how badly it  
>>> would fail.
>>>
>>> simply not attuned to what I am confident of being able to  
>>> deliver in this space. So rather than embarking on a major  
>>> struggle with material for the next month to try and prepare  
>>> material that would align to what you are proposing, with a  
>>> pretty confident expectation of being unable to meet the goals  
>>> you've outlined, it would be best if I simply let you know now  
>>> that your proposed realignment of the tutorial would not work for  
>>> me. I am of course quite happy for the edu team to find someone  
>>> else who would be more confident of being able to prepare  
>>>> I realize that we're asking a lot, and we trust you to do the  
>>>> best you can.  Although this may be a difficult task, you are,  
>>>> IMO, the most likely person to be able to pull it off.
>>>> what the operations folks mean when they talk about issues in  
>>>> the routing system, because we don't really know that  
>>>> terminology.  I've had multiple smart folks sit through talks on  
>>>> the route table growth in the DFZ and then lean over to me and  
>>>> ask me if I know what the DFZ is, for example.  Many of us don't  
>>>> really know if you are talking about routes on a single router,  
>>>> the union of all DFZ routes, the average number of routes per  
>>>> router or what...  Most of us don't really understand how  
>>>> peering works.  And some people (including me) don't understand  
>>>> what it would mean to put a level of indirection (such as LISP  
>>>> or other tiered routing schemes) somewhere in the Internet (not  
>>>> at the enterprise or DFZ boundary), because we don't understand  
>>>> what interesting levels exist between an enterprise and the DFZ,  
>>>> if any.
>>>>> causes my brain to hurt. I suppose that from my perspectives  
>>>>> such topics as:
>>>>>
>>>>> are all topics that can either be treated quickly,  
>>>>> superficially and poorly or topics that take ages to get into  
>>>>> and assume a massive amount of familiarity with routing that  
>>>>> you probably know the answers already.
>>>>>
>>>>> Having said that you are making a Big Ask here, I must admit  
>>>>> that the room in Chicago surprised me - many of the folk there  
>>>>> knew all about BGP the protocol and were asking for what you  
>>>>> are asking
>>>>>
>>>>>> kinds of issues are people trying to solve with policies  
>>>>>> (e.g., I want to connect to A so A's
>>>>>> customers can talk to my customers, and want to connect to B  
>>>>>> so B's customers can talk
>>>>>> directly to my customers, but I don't want to let A and B use  
>>>>>> me as a through path)? (and
>>>>>> actually, that is about the only example people give -- can  
>>>>>> you give others?)
>>>>>> because you get paid more money? Or is everything a flat rate  
>>>>>> so you are motivated to do
>>>>>> as little work as possible? Are the charging policies flat  
>>>>>> rate (if they are) because the protocols
>>>>>>> Thanks for presenting the IDR Tutorial at IETF 69.  As  
>>>>>>> always, you did an excellent job of preparing and presenting  
>>>>>>> your session.
>>>>>>>
>>>>>>> However, the EDU Team discussed your tutorial and the  
>>>>>>> feedback we received, and we have some thoughts about how to  
>>>>>>> update the tutorial so that it will be even more useful to  
>>>>>>> the IETF community.
>>>>>>>
>>>>>>> and why is it interesting?  Who peers with whom at what  
>>>>>>> levels? What types of BGP filters do they use in which  
>>>>>>> directions?  What controls are in place to prevent random BGP  
>>>>>>> routes from hitting the DFZ?  What types of things can (and  
>>>>>>> do) go wrong with the current system?  etc...
>>>>>>>
>>>>>>> So, we'd be interested in seeing more of an introduction to  
>>>>>>> the Internet IDR routing system than just an intro to BGP...
>>>>>>>

---

From: Radia Perlman <[email-masked]>
Date: Tue, 16 Oct 2007 11:16:44 -0700

I think you should lean on him to put in at least some of the stuff you 
(and I). How long could it
possibly take to define DFZ? There's lots of stuff he could take out 
(packet formats for BGP,
for instance, definition of link state and distance vector protocols) if 
the issue is amount of time.
He doesn't have to cover *all* the things we suggested, and certainly 
not in any great detail.
So as long as he's not claiming to not know the answers to these things, 
I think we should ask
him to downplay the packet formats, get rid of non-IDR protocols 
entirely, and put as much
of the folklore of interdomain topology/politics into the talk as 
possible, given the time constraint.

Radia