Hi Qin,
Thanks for the work on TE performance metrics. Here are some quick comments:
- It is not fully clear to me if you want to consider linkdelay,
linkjitter, ... as new Cost Metrics also or they will be only constraints
of the "routingcost" Cost Metric. Does it make sense to consider them as
Cost Metrics?
- If so, a feedback is that ALTO Cost Metric need to follow the RFC 6390:
6390 Guidelines for Considering New Performance Metric Development. A.
Clark, B. Claise. October 2011. (Format: TXT=49930 bytes) (Also
BCP0170) (Status: BEST CURRENT PRACTICE)
In particular, Sec. 5.4 of RFC 6390 specifies a template for specifying
additional performance metrics (Cost Metrics). I believe that we will
follow the template. As an example, the template specifies Units of
Measurement (item iv) which are missing in the draft. How about we follow
the template?
- In your example json:
"data": {
"cost type": {
"cost-mode": "numerical",
"cost-metric":"routingcost"},
"constraints" : {"linkdelay"},
"endpoints": {
"srcs": [ "ipv4:192.0.2.2" ],
"dsts": [
"ipv4:192.0.2.89",
"ipv4:198.51.100.34",
"ipv4:203.0.113.45"
]
}
// YRY: missing <- "}" ?
"map": {
"ipv4:192.0.2.2": {
"ipv4:192.0.2.89": 0.0[linkdelay eq 0.0],
"ipv4:198.51.100.34": 15.0[linkdelay eq 3.0],
"ipv4:203.0.113.45": 1.0[linkdelay eq 12.0],
}
}
Is the example query or response? I understand that they are response, but
I feel that it can be helpful to start with specifying the input of
filtering. Let's see if my understanding of your input is correct. The
current spec is:
object {
CostType cost-type;
[JSONString constraints<0..*>;]
[PIDFilter pids;]
} ReqFilteredCostMap;
object {
PIDName srcs<0..*>;
PIDName dsts<0..*>;
} PIDFilter;
You appear to extend the request format to be:
object {
CostType cost-type;
[JSONString constraints<0..*>;]
[Endpoints endpoints;] // YRY: new?
[PIDFilter pids;]
} ReqFilteredCostMap;
I feel that you are extending the syntax of "constraints" (see top of page
49 of -17). Will it be helpful to define the grammar first?
- Regarding response, I read that you want the response to include the
values of multiple attributes. For example, from your example, you are
trying to say that:
from "ipv4:192.0.2.2" to "ipv4:198.51.100.34"
has routing cost 15 and delay 3. Is this correct? There are discussions on
extending the map to report multiple attributes., and personally, I will
find the following format easier to read (more symmetric):
ipv4:198.51.100.34": ["routingcost": 15.0, "linkdelay":3.0],
Please let me know if I understand you correctly.
Thanks!
Richard
On Mon, Jul 8, 2013 at 3:48 AM, Qin Wu <[email protected]> wrote:
> Hi,folks:
> Here is the initial draft (v-00)to discuss Json format representation
> for TE performance metrics advertised by OSPF in the ALTO
> information resource Directory.
> The URL link is available at:
> http://tools.ietf.org/html/draft-wu-alto-json-te-00
> Your comments and feedback are welcome!
>
> Regards!
> -Qin
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> On Behalf Of [email protected]
> Sent: Monday, July 08, 2013 3:21 PM
> To: [email protected]
> Subject: I-D Action: draft-wu-alto-json-te-00.txt
>
> A New Internet-Draft is available from the on-line Internet-Drafts
> directories.
>
>
> Title : JSON Format Extensions for Traffic Engineering
> (TE) performance metrics in the ALTO Information Resource Directory
> Author(s) : Qin Wu
> Liang Xia
> Filename : draft-wu-alto-json-te-00.txt
> Pages : 16
> Date : 2013-07-08
>
> Abstract:
> The base ALTO specification defines two properties for cost metric
> attribute in the Cost MAP, including 'hopcount' and 'routingcost'.
> This specification adds five new properties and one new parameter for
> Traffic Engineering(TE) performance related constraint attribute
> associated with cost metric attribute 'routingcost' in the ALTO
> Information Resource Directory: Link Delay, Delay Variation, Packet
> Loss, Residual Bandwidth, Available Bandwidth,linkstate.
>
>
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-wu-alto-json-te
>
> There's also a htmlized version available at:
> http://tools.ietf.org/html/draft-wu-alto-json-te-00
>
>
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
>
> _______________________________________________
> I-D-Announce mailing list
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> Internet-Draft directories: http://www.ietf.org/shadow.html
> or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
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