Re: [alto] WG chair review of draft-ietf-alto-deployments-14

Mon, 23 May 2016 00:13:48 -0700 

Vijay, Sebastian,
all,

Since most of the issues are already addressed I have only a few comments.

Details inline.


On 17.05.2016 23:51, Vijay K. Gurbani wrote:

On 05/09/2016 03:56 PM, Sebastian Kiesel wrote:


- S2.2.1, second paragraph: "4. Resource consumer (using the ALTO
guidance)".
  Here, what context does the phrase "using the ALTO guidance"
impart? Does
  not the ALTO client also uses the ALTO guidance?  Is the guidance
provided
  to a resource consumer different than the one provided to a
client? Where
  have you made the distinction between an ALTO client and a resource
  consumer?  Later on in S3.2.2 you make a distinction by qualifyin an
  application as a resource consumer; perhaps you can make this
distinction up
  front.


See my thought on the terminology above ... When we combine the
terminology definitions of RFC 5693 with the ALTO core specification
RFC 7285, the outcome would IMO be:

An ALTO client is basically a HTTP client library, a JSON parser
library, and some data structures, which does not need guidance itself.
It is linked into the resource consumer (i.e., for example the specific
BitTorrent client process running on your computer), because the latter
needs the guidance.


OK, so this is good.  How about imparting this definition in the I-D,
something like the following:

OLD: (S2.2.1)
  An ALTO deployment involves four kinds of entities:

   1.  Source of topological information

   2.  ALTO server

   3.  ALTO client

   4.  Resource consumer (using the ALTO guidance)

NEW: (S2.2.1)
An ALTO deployment involves four kinds of entities:

   1.  Source of topological information

   2.  ALTO server

   3.  ALTO client

   4.  Resource consumer (using the ALTO guidance)
   (We differentiate between an ALTO client and a Resource Consumer
    as follows: an ALTO client will be composed of software implementing
    a HTTP client library, a JSON parser library and some data
    structures representing the ALTO maps.  This library will be
    linked in to a Resource Consumer, which could be thought of as
    the process executing on a host communicating with an ALTO
    server.)


This is a good clarification but now we have two consecutive parentheses.
Do we really need the clarification that the resource consumer is the one
using the guidance here? I think it is better to include this in the previous 
section.

-S2.1.1, third bullet under "ALTO CLlient"
    s/in the resource consumer and/or in the resource directory./
       in the resource consumer and/or in the resource directory which are
       using the ALTO guidance.




- S3.2.4, first bullet under "Distance-related rating criteria:"
  s/values, and the ALTO client will not be informed about the
nature of the
  information./values.


why?

this sentence has two aspects:
- the server is free to chose how to compute the values, and
- the server does not even have to tell the client how he did it

both are important


OK, in that case, I would suggest
s/nature of the information./nature of the computation./

This makes it more direct that there are two aspects as you point
out above.


Agree.
- S3.5.3, Figure 13: For the sake of completeness and symmetry, you should specify the costs for the links that joins (PID 3, PID 1), as well as the 
  text that makes it costly for peers in PID 3 to get content from
PID 1, but
  not as costly to get content from PID 2.


Who contributed this example?  Hans?  Can you do that?


Will need to close this soon.  Can you please drive this to completion
with Hans?


This section is not from me but I took the liberty to modify it. Details
in the attached file.




- S3.6.1, Figure 15: What would be good is if the link weights in
this figure
  were also reflected in Figure 14.  That way, later on when one is
  interpreting the hopcount cost map (Figure 20), it is easy to see
that the
  path weight between R1->R3->R4->R9 is 40.


Who contributed this example?  Hans?  Can you do that?


Will need to close this soon.  Can you please drive this to completion
with Hans?
It is a good idea and modified the figure accordingly. Details in the attached file. 

Hans
Title: Diff: draft-ietf-alto-deployments-14.txt - draft-ietf-alto-deployments-14._mod.txt
 draft-ietf-alto-deployments-14.txt   draft-ietf-alto-deployments-14._mod.txt 
skipping to change at page 40, line 6 skipping to change at page 40, line 6
access networks AN A and AN B, which are also connected to the access networks AN A and AN B, which are also connected to the
backbone network. In this network structure, the mobile network can backbone network. In this network structure, the mobile network can
be defined as one optimization area, and PID 1 can be assigned to it. be defined as one optimization area, and PID 1 can be assigned to it.
Access networks AN A and B can also be defined as optimization areas, Access networks AN A and B can also be defined as optimization areas,
and PID 2 and PID 3 can be assigned, respectively. The cost values and PID 2 and PID 3 can be assigned, respectively. The cost values
are then defined as shown in Figure 13. are then defined as shown in Figure 13.
To decrease the usage of wireless link, the relationship of these To decrease the usage of wireless link, the relationship of these
costs can be defined as follows: costs can be defined as follows:
From view of mobile network: C4 < C1. This means that clients in From view of mobile network: C4 < C1 and C4 = C8. This means that
mobile network requiring data resources from other clients will clients in mobile network requiring data resources from other
prefer clients in AN A to clients in the mobile network. This policy clients will prefer clients in AN A ot B to clients in the mobile
can decrease the usage of wireless link and power consumption in network. This policy can decrease the usage of wireless link and
terminals. power consumption in terminals.
From view of AN A: C2 < C6, C5 = maximum cost. This means that From view of AN A: C2 < C6, C5 = maximum cost. This means that
clients in other optimization area will avoid retrieving data from clients in other optimization area will avoid retrieving data from
the mobile network. the mobile network.
From view of AN B: Analog to the view of AN A, C3 < C8 and C9 =
maximum cost.
+-----------------------------------------------------------------+ +-----------------------------------------------------------------+
| | | |
| ISP A +-------------+ | | ISP A +-------------+ |
| +--------+ ALTO +---------+ | | +--------+ ALTO +---------+ |
| | | Service | | | | | | Service | | |
| | +------+------+ | | | | +------+------+ | |
| | | | | | | | | |
| | | | | | | | | |
| | | | | | | | | |
| +-------+-------+ | C6 +--------+------+ | | +-------+-------+ | C6 +--------+------+ |
| | AN A |<--------------| AN B | | | | AN A |<--------------| AN B | |
| | PID 2 | C7 | | PID 3 | | | | PID 2 | C7 | | PID 3 | |
| | C2 |-------------->| C3 | | | | C2 |-------------->| C3 | |
| +---------------+ | +---------------+ | | +---------------+ | +---------------+ |
| ^ | | | ^ | | ^ | | | ^ |
| | | | | | | | | | | | | |
| | |C4 | | | | | | | C4 | C8 | | |
| C5 | | | | | | | C5 | | | | | C9 |
| | | +--------+---------+ | | | | | | +--------+---------+ | | |
| | +-->| Mobile Network |<---+ | | | | +-->| Mobile Network |<---+ | |
| | | PID 1 | | | | | | PID 1 | | |
| +------- | C1 |----------+ | | +------- | C1 |----------+ |
| +------------------+ | | +------------------+ |
+-----------------------------------------------------------------+ +-----------------------------------------------------------------+
Figure 13: ALTO deployment in ISPs with mobile network Figure 13: ALTO deployment in ISPs with mobile network
These examples show that for ALTO in particular the relationships These examples show that for ALTO in particular the relationships
skipping to change at page 42, line 11 skipping to change at page 42, line 11
five different routers (R2, R5, R6, R7 and R9). Each client network five different routers (R2, R5, R6, R7 and R9). Each client network
has a /56 prefix with 2001:db8:1:x00:: (x = [1..5]) as network has a /56 prefix with 2001:db8:1:x00:: (x = [1..5]) as network
address. address.
+-------------------+ +-----+ +-----+ +-------------------+ +-------------------+ +-----+ +-----+ +-------------------+
|2001:db8:1:200::/56+----+ R6 | | R7 +----+2001:db8:1:300::/56| |2001:db8:1:200::/56+----+ R6 | | R7 +----+2001:db8:1:300::/56|
+-------------------+ +--+--+ +--+--+ +-------------------+ +-------------------+ +--+--+ +--+--+ +-------------------+
| | | |
+---------------+ | | +---------------+ | |
| AS 2 | | | | AS 2 | | |
|2001:db8:2::/48| | | |2001:db8:2::/48| | 10 | 10
+------------+--+ | | +------------+--+ | |
| | | | | |
| | | | | |
+--+--+ +--+--+ +--+--+ +-------------------+ +--+--+ 15 +--+--+ +--+--+ +-------------------+
| R1 +--------+ R3 +----+ R5 |----+2001:db8:1:400::/56| | R1 +--------+ R3 +----+ R5 |----+2001:db8:1:400::/56|
+--+--+ +--+--+ +--+--+ +-------------------+ +--+--+ +--+--+ 5 +--+--+ +-------------------+
| \ / | | | \ / | |
| \ / | | | \ / 15 | |
| \ / | | +---------------+ | \ / | | +---------------+
| \/ | | | AS 4 | | \/ | | | AS 4 |
| /\ | | |2001:db8:4::/48| | 20 /\ | 5 | 10 |2001:db8:4::/48|
| / \ | | +-------+-------+ | / \ | | +-------+-------+
| / \ | | | | / \ 20 | | |
| / \ | | | | / \ | | |
+--+--+ +--+--+ +--+--+ +-------+-------+ +--+--+ +--+--+ +--+--+ +-------+-------+
| R2 | | R4 | | R8 +--------+ AS 3 | | R2 | | R4 | | R8 +--------+ AS 3 |
+--+--+ +--+--+ +--+--+ |2001:db8:3::/48| +--+--+ +--+--+ +--+--+ |2001:db8:3::/48|
| | | +---------------+ | | | +---------------+
| | | | | | 10
| | | | | 20 |
+------------+------+ | +--+--+ +-------------------+ +------------+------+ | +--+--+ +-------------------+
|2001:db8:1:100::/56| +-------+ R9 +----+2001:db8:1:500::/56| |2001:db8:1:100::/56| +-------+ R9 +----+2001:db8:1:500::/56|
+-------------------+ +-----+ +-------------------+ +-------------------+ +-----+ +-------------------+
Figure 14: Example network Figure 14: Example network
The example network utilizes two different routing protocols, one for The example network utilizes two different routing protocols, one for
IGP and another for EGP routing. The used IGP is a link-state IGP and another for EGP routing. The used IGP is a link-state
protocol such as IS-IS. The applied link weights are shown in protocol such as IS-IS. The applied link weights are anotated in the
Figure 15. To obtain the topology and routing information from the graph and additionally shown in Figure 15. All links are bidirectional
network, the topology data source must be connected directly to one and their weights are symmetric. To obtain the topology and routing
of the routers (R1...R9). Furthermore, the topology data source must information from the network, the topology data source must be
be enabled to communicate with the router and vice versa. connected directly to one of the routers (R1...R9). Furthermore, the
topology data source must be enabled to communicate with the router
and vice versa.
The Border Gateway Protocol (BGP) is used in this scenario to route The Border Gateway Protocol (BGP) is used in this scenario to route
between autonomous systems (AS). External BGP is running on the two between autonomous systems (AS). External BGP is running on the two
border routers R1 and R8. Furthermore, internal BGP is used to border routers R1 and R8. Furthermore, internal BGP is used to
propagate external as well as internal prefixes within the network propagate external as well as internal prefixes within the network
boundaries. It is running on every router with an attached client boundaries. It is running on every router with an attached client
network (R2, R5, R6, R7 and R9). Since no route reflector is present network (R2, R5, R6, R7 and R9). Since no route reflector is present
it is necessary to fetch routes from each BGP router separately. it is necessary to fetch routes from each BGP router separately.
R1 R2 R3 R4 R5 R6 R7 R8 R9 R1 R2 R3 R4 R5 R6 R7 R8 R9
 End of changes. 11 change blocks. 
21 lines changed or deleted 26 lines changed or added

This html diff was produced by rfcdiff 1.42. The latest version is available from http://tools.ietf.org/tools/rfcdiff/ 
_______________________________________________
alto mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/alto

Reply via email to