Dear Richard,
The longest prefix matching mechanism in ALTO maps each IP address into a
single PID, this is the non-overlapping property of an ALTO network map. But
in the end-to-end
policies such as GBP, EPGs may be overlapped, some endpoints may belong to
multiple EPGs, the longest prefix matching mechanism should be changed to adapt
for that.
I think that one prefix or IP address can be mapped into a PID list that
contains one or multiple PIDs. We can still use the longest prefix matching,
but the result is a PID list,
not a single PID.
I also like the first approach. There is only one cost map, but the cost metric
has a policy list, each policy has multiple fields, like Protocol, Port, QoS
parameters, or other fields.
"multi-cost-types" : [
{"cost-mode": "policy", "cost-metric": "policy"},
{"cost-mode": "policy", "cost-metric": "policy"}
]
}
"cost-map" : {
"PID1": { "PID1":[null,null], "PID2":[<TCP,80,10M>,<UDP,120,20M>]},
"PID2": { "PID1":[<TCP,80,10M>,<UDP,120,20M>], "PID2":[null,null]}
}
-----原始邮件-----
发件人:"Y. Richard Yang" <[email protected]>
发送时间:2015-04-10 02:15:49 (星期五)
收件人: "郭华明" <[email protected]>
抄送: ChenGuohai <[email protected]>, "[email protected]" <[email protected]>
主题: Re: RE: [alto] ALTO extension for representing SDN policies
Dear Huaming, Guohai,
Thanks for sharing the on the ALTO list.
I infer that the bigger picture you are thinking is to use ALTO maps to convey
end-to-end policies such as group based policies (GBP). The idea of an endpoint
group (EPG) in GBP is the same as the PID in ALTO. In fact, initially PID was
named as EPG.
Regardless of which one of the two approaches mentioned in your email, one gap
(of encoding GBP using an ALTO map) I see is that eventually the ALTO WG has
decided that there must be a mechanism to map each endpoint into a single PID,
and the longest prefix matching mechanism is the chosen mechanism. I assume
that you require the same?
Between the two approaches, the first one maps more naturally into the current
ALTO usage model. But my understanding is that you will then have multiple
correlated cost maps, and there needs to be an ordering in searching the maps.
For example, one map has port=*, while the next has port=80. I assume that you
need to define some kind of priority/maximum matching to define precisely the
semantics. I do not understand why you need QoS as a multiplex selector.
Thanks!
Richard
On Thu, Apr 9, 2015 at 10:49 AM, 郭华明 <[email protected]> wrote:
Hi Guohai,
I think your example is good, it's my opinion that more meaningful policies are
helpful for traffic optimization.
-----原始邮件-----
发件人:ChenGuohai <[email protected]>
发送时间:2015-04-08 21:18:44 (星期三)
收件人: "郭华明" <[email protected]>, "Richard Yang Y." <[email protected]>
抄送: "[email protected]" <[email protected]>
主题: RE: [alto] Alto extension for representing SDN policies
Hi Huaming,All
Getting policy rules does benefit to traffic optimization. In addition to that
it can reduce ALTO request and response.
For example, a policy is that band between a pair of src(A)and dst is 20M
between 11:00 to 14:00 and is 10M for other time. And band between other
src(B,C,D ....) and this dst is 15M. The ALTO client can use this policy in
selecting more optimal peers without sending ATLO cost map request to ALTO
server now and then.
ALTO client select src(A) as the peer between 11:00 to 14:00 and one of
src(B,C,D....) at other time.
Make sense?
BR
Guohai
Date: Tue, 31 Mar 2015 04:23:49 +0800
From: [email protected]
To: [email protected]
CC: [email protected]
Subject: [alto] Ato extension for representing SDN policies
Hi Richard, All
In SDN, each pair of source and destination network could have multiple policy
rules. These rules maybe include source/destination address, protocols, ports,
QoS, actions and so on. This information is
also important attributes of the path.
I am thinking that if some policy information could be provided for
applications in Alto, this is also helpful for traffic optimization.
I think there are two methods to do that in Alto.
1, Use a multiple cost types in Cost Maps (similar ideas in
), add a new Cost Mode: policy, the Cost Metric use multiple fields, like
<Protocol, Port, QoS>, to represent a policy.
2, Add a new map service, like Policy Maps Service. In Policy Maps,
applications can get the policy rule information.
Thanks.
--
----------------
Best!
Huaming Guo
China Academy of Information and Communications Technology (CAICT)
_______________________________________________ alto mailing list
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--
----------------
Best!
Huaming Guo
China Academy of Information and Communications Technology (CAICT)
--
--
=====================================
| Y. Richard Yang <[email protected]> |
| Professor of Computer Science |
| http://www.cs.yale.edu/~yry/ |
=====================================
--
----------------
Best!
Huaming Guo
China Academy of Information and Communications Technology (CAICT)_______________________________________________
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