Hi Qin,
Thanks you. I still have some questions, please see my reply inline below.
Peng Liu | 刘鹏
China Mobile | 移动研究院
mobile phone：13810146105
email: liupeng...@chinamobile.com
Hi WG,
Here are some considerations of recharter:
I believe that the multi domain problem is worthy of attention. At present,
operators also research in it, which may involve guaranteeing end-to-end
network service in the future, such as delay, bandwidth, etc. There are some
researches on cross domain deterministic network in the industry, which need
some support from management and control plane.
[Qin]: thanks for sharing your use case, I think we may have many multi-domain
applications. Multiple domain setting is not only referred to multiple
administrative domains belonging to the same operator but also referred to
cross operator domains.
[Peng]: Yes, we can easily find the usecase of cross operators domains such as
home broadband.
Detnet can be a good use case for muit-domain setting, we may also consider
many other use cases such as traffic from source to destination spanning
across multiple administrative domain, the computing and storage are
distributed in different administrative domain
[Peng]: DetNet WG only solves the problem of single domain, because multi
domain brings much more challenge to the deterministic latency guarantee. It
may be difficult to implement strict multi domain deterministic latency
guarantee now, but we may gradually optimize it.
Which require resource discovery or multi domain SFC case.
As stipulated by RFC7971, there is the network consisting of multiple domains
and in many cases it is not possible to collect information across network
borders. This issue can be addressed by deploying ALTO server in each domain
with hierarchy design or mesh design, and allow server to server communication.
In addition, we need to consider multi domain connectivity discovery, multi
domain service discovery.
[Peng]: I agree that it is difficult 'to collect information across network
borders', and can you explain more about the "hierarchy design or mesh design"?
For the 'multi domain connectivity discovery, multi domain service
discovery', is there any usecase or requirements can be found now?
Who is the provider of Alto service is related to the deployment and
cooperation mode. It may be difficult for operators to give too much detailed
network information now. If the Alto service belongs to the operator, it may be
used to help manage its own network. If Alto service belong to non operators, I
think the issue of how to cooperate needs further discussion.
[Qin]:I think one good use case we have is MOWIE use case, i.e., adjust the
bitrate to improve Cloud gaming QoE experience based on abstract network
information to be exposed. For this use case, we can see a good collaboration
between OTT provider and network operation, Probably they sign agreement for
the mutual benefits reason. Also network operator will provide aggregate and
abstract network information and expose very few information to the client,
this is what ALTO is designed for.
The proposed work items related to MOWIE, feel free to review and evaluate it'
[Peng]: Thanks. I talked to Gang about MOWIE before. It involves some new
cooperation modes, which are worthy of further discussion and exploration in
details.
o Protocol extensions to support a richer and extensible set of policy
attributes in ALTO information update request and response. Such policy
attributes may indicate information dependency (e.g., ALTO path-cost/QoS
properties with dependency on real-time network indications), optimization
criteria (e.g., lowest latency/throughput network performance objective), and
constraints (e.g., relaxation bound of optimization criteria, domain or network
node to be traversed, diversity and redundancy of paths).
o Protocol extensions for facilitating operational automation tasks and
improving transport efficiency. In particular, extensions to provide "pub/sub"
mechanisms to allow the client to request and receive a diverse types (such as
event-triggered/sporadic, continuous), continuous, customized feed of
publisher-generated information. Efforts developed in other working groups
such as MQTT Publish / Subscribe Architecture, WebSub, Subscription to YANG
Notifications will be considered, and issues such as scalability (e.g., using
unicast or broadcast/multicast, and periodicity of object updates) should be
considered.
”
Thanks!
Regards,
Peng
Peng Liu | 刘鹏
China Mobile | 移动研究院
mobile phone：13810146105
email: liupeng...@chinamobile.com
发件人: Qin Wu
时间: 2021/02/22(星期一)21:45
收件人: IETF ALTO;
抄送人: alto-chairs;alto-ads;
主题: [alto] ALTO Draft ReCharter WG review
Hi, :
We have requested one hour session for ALTO WG meeting in the upcoming IETF
110, which is arranged on Friday, March 12, 14:30-15:30(UTC).
The goal is to boil down ALTO recharter and have consensus on charter contents
in IETF 110.
To get this goal, an updated inline draft charter text for ALTO has just been
posted to this list,
This charter has received a couple of rounds of informal review from WG
members, chairs and our Ads from brief to deep thorough, 5 new chartered items
have been listed.
We would like to solicit feedback on these new chartered items and your use
case, deployment, idea corresponding to these new chartered items.
Sharing your past deployment story will also be appreciated.
============================================================================================
The ALTO working group was established in 2008 to devise a request/response
protocol to allow a host to benefit from a server that is more cognizant of
the network infrastructure than the host is.
The working group has developed an HTTP-based protocol and recent work has
reported large-scale deployment of ALTO based solutions supporting
applications such as content distribution networks (CDN).
ALTO is now proposed as a component for cloud-based interactive applications,
large-scale data analytics, multi-cloud SD-WAN deployment, and distributed
computing. In all these cases, exposing network information such as abstract
topologies and network function deployment location helps applications.
To support these emerging uses, extensions are needed, and additional
functional and architectural features need to be considered as follows:
o Protocol extensions to support a richer and extensible set of policy
attributes in ALTO information update request and response. Such policy
attributes may indicate information dependency (e.g., ALTO path-cost/QoS
properties with dependency on real-time network indications), optimization
criteria (e.g., lowest latency/throughput network performance objective), and
constraints (e.g., relaxation bound of optimization criteria, domain or network
node to be traversed, diversity and redundancy of paths).
o Protocol extensions for facilitating operational automation tasks and
improving transport efficiency. In particular, extensions to provide "pub/sub"
mechanisms to allow the client to request and receive a diverse types (such as
event-triggered/sporadic, continuous), continuous, customized feed of
publisher-generated information. Efforts developed in other working groups
such as MQTT Publish / Subscribe Architecture, WebSub, Subscription to YANG
Notifications will be considered, and issues such as scalability (e.g., using
unicast or broadcast/multicast, and periodicity of object updates) should be
considered.
o The working group will investigate the configuration, management, and
operation of ALTO systems and may develop suitable data models.
o Extensions to ALTO services to support multi-domain settings. ALTO is
currently specified for a single ALTO server in a single administrative
domain, but a network may consist of
multiple domains and the potential information sources may not be limited to a
certain domain. The working group will investigate extending the ALTO
framework to (1) specify multi-ALTO-server protocol flow and usage guidelines
when an ALTO service involves network paths spanning multiple domains with
multiple ALTO servers, and (2) extend or introduce ALTO
services allowing east-west interfaces for multiple ALTO server integration and
collaboration. The specifications and extensions should use existing services
whenever possible. The specifications and extensions should consider realistic
complexities including incremental deployment, dynamicity, and security issues
such as access control, authorization (e.g., an ALTO server provides
information for a network that the server has no authorization), and privacy
protection in multi-domain settings.
o The working group will update RFC 7971 to provide operational considerations
for recent protocol extensions (e.g., cost calendar, unified properties, and
path vector) and new extensions that the WG develops. New considerations will
include decisions about the set of information resources (e.g., what metrics to
use), notification of changes either in proactive or reactive mode (e.g., pull
the backend, or trigger just-in-time measurements), aggregation/processing of
the collected information (e.g., compute information and network information
)according to the clients’ requests, and integration with new transport
mechanisms (e.g., HTTP/2 and HTTP/3).
When the WG considers standardizing information that the ALTO server could
provide, the following criteria are important
to ensure real feasibility:
- Can the ALTO server realistically provide (measure or derive) that
information?
- Is it information that the ALTO client cannot find easily some other way?
- Is the distribution of the information allowed by the operator of the
network? Does the exposure of the information introduce privacy and
information leakage concerns?
Issues related to the specific content exchanged in systems that make use of
ALTO are excluded from the WG's scope, as is the issue of dealing with
enforcing the legality of the content. The WG will also not propose standards
on how congestion is signaled, remediated, or avoided.
-Qin Wu (on behalf of chairs)_______________________________________________
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