Hi Richard,
Thanks for sharing your idea！ I think it's necessary to considering the
security and privacy issues.
The framework of differential privacy can be a potential choice to protect
individual or detail privacy of network without encryption which might influent
the efficiency of information exchange, while it need to consider the data
availability.
Regards,
Peng
Peng Liu | 刘鹏
China Mobile | 移动研究院
mobile phone：13810146105
email: liupeng...@chinamobile.com
发件人: Y. Richard Yang
时间: 2021/03/10(星期三)10:32
收件人: Qiao Xiang;
抄送人: 刘鹏;IETF ALTO;Qin Wu;
主题: Re: [alto] ALTO Draft ReCharter WG review
Hi Peng, all,
Thanks a lot for the excellent discussions. It is clear that multi-domain is a
major issue to resolve, as multidomain is the general deployment setting where
resource consumers and providers are in the general case deployed in multiple
networks.
To proceed with the recharter discussion, I suggest that we conduct basic
security and privacy analysis to see if we are ready for recharter; that is, we
have a basic understanding of related issues so that it is ready for design,
not still in the early research stage. For security, we can start with focusing
on the basic requirements including authenticity, integrity, and
confidentiality. For privacy, we can start with a framework such as
differential privacy analysis.
To me, a basic model of a multi-domain alto information service is the
following:
- a set of (potential) resource providers s1, s2, ...,
- a set of (potential) resource consumers c1, c2, c3, ...
The foundation of the alto service is to provide the costs of the paths {si ->
cj}; I always think of alto as an extension of DNS, which is mainly for
endpoints in a graph and alto is paths. In a single domain setting, all
entities, {si}, {cj}, {si->cj} are within a single domain and hence the main
security/privacy issue is the security/privacy issue of between the single alto
server representing the single domain and the alto client. For security, the
domain can leverage any one of the security systems (e.g., using public keys to
bootstrap the system); for privacy, the application (client) and the network
(server) are two parties, and they can agree on an acceptable privacy model.
Now, in a multi-domain setting, each entity may have a different domain (or a
sequence of domains for a path). Now, both ALTO client and ALTO server will
have additional security and privacy issues.
- For the ALTO client, the information can now come from multiple networks;
assume the information info(n1, n2, ...) is computed from those from multiple
networks n1, n2, ... Then the basic security issue is how the client can verify
the authenticity of the information.
- For an ALTO server, the server may not have a direct trust relationship with
the client; for example, when the ALTO server is only in the chain of a path,
not the client-facing server. Hence, the server may not have a relationship to
specify the privacy requirement.
The preceding are challenging issues. It is clear that security and privacy
issues depend on the specific design. Hence, we target a "lower-bound"
analysis, by considering a base design that can address main security and
privacy issues. The WG can decide on the specific design which is better than
the basic design.
During the design meetings, we have considered the following "base-line" design
for a "lower-bound":
- We provide a basic path discovery service to discover the path segments. We
can use BGP security to bootstrap the security of the discovered paths.
- We build verifiable aggregation (i.e., the preceding info function) so that
the information can then be individually verified.
- The remaining issue is how each server can control the privacy of its
information, as it may not have a direct relationship with the client. For
this, we suggest to start with basic public information, and gradually build
trust.
The preceding is high level. A first task, if multidomain is charted, is to
write down the details, beyond the existing drafts. I do agree that this
analysis and requirements is a good starting, based on the specified use cases.
We can go over the details in our design meeting in the next few following
weeks.
Richard
On Tue, Mar 2, 2021 at 11:18 AM Qiao Xiang <xiang...@gmail.com> wrote:
Hi Peng, Qin and Richard,
Very good discussion! Richard and I have been working with folks from CMS and
ESNet (a large global multi-domain science network) to design network
information exposure abstractions and mechanisms in multi-domain networks, with
privacy requirements considered. The basic idea stems from the ALTO path-vector
extension but goes beyond to take privacy into consideration. The following are
some pointers.
[1] "Toward Fine-Grained, Privacy-Preserving, Efficient Multi-Domain Network
Resource Discovery", IEEE JSAC, 2019.
(https://ieeexplore.ieee.org/abstract/document/8756056)
[2] "Resource Orchestration for Multi-Domain, Exascale, Geo-Distributed Data
Analytics",
(https://datatracker.ietf.org/doc/draft-xiang-alto-multidomain-analytics/)
For the pointers above, the privacy requirement considered in this work is that
the network information of multiple domains should be exposed to applications
as a complete, unified aggregation, appearing as much as possible as from a
single (virtual) network. We design a network information obfuscation mechanism
so that the application is not able to associate any network resource
bottleneck information to any domain, reducing the risk of exposing network
vulnerability.
In addition, we also studied how to control the routing across multiple domains
to achieve more flexible end-to-end interdomain routing. Essentially, we
propose a mechanism that allows networks to expose their available interdomain
routes, just as BGP looking glasses, so that applications can control them. In
this setting, we consider the privacy setting where each network's BGP export
policies are private, and design interesting algorithms for applications to
select the best policy-compliant routes without knowing the export policies.
The following is the pointer for this study:
[3] "Toward Optimal Software-Defined Interdomain Routing". INFOCOM 2020
(https://ieeexplore.ieee.org/abstract/document/9155486)
Above are our current efforts on extending ALTO to multi-domain settings. It
would be great if we can know more about the industry efforts on network
information exposure in multi-domain settings, and the privacy requirements of
operators. This would be extremely helpful to push this extension forward! :-)
Best
Qiao
On Tue, Mar 2, 2021 at 1:14 PM 刘鹏 <liupeng...@chinamobile.com> wrote:
Hi Richard,
Thank you. please see my reply inline below.
Peng Liu | 刘鹏
China Mobile | 移动研究院
mobile phone：13810146105
email: liupeng...@chinamobile.com
发件人: Y. Richard Yang
时间: 2021/03/02(星期二)07:36
收件人: 刘鹏;
抄送人: IETF ALTO;Qin Wu;
主题: Re: [alto] ALTO Draft ReCharter WG review
Dear Peng,
Thank you so much for the feedback. Please see below.
On Fri, Feb 26, 2021 at 9:23 PM 刘鹏 <liupeng...@chinamobile.com> wrote:
Hi WG,
Here are some considerations of recharter:
I believe that the multi domain problem is worthy of attention.
It is good info.
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.
Do you want to share some pointers?
[Peng] As Qin said, it is hard to collect information across network borders.
Just taking deterministic network as an example, it is hard to applying
synchronization, unified forwarding strategy in multi domain, so there are some
works need to be done with management plane. Due to the large scale and multi
domains or operators, the management system may be distributed.
A potential way is to consider negotiating the forwarding time of each domain
in advance and carrying time stamp in the message to control the forwarding
path of each domain. While it needs some agreements like contracts to prevent
one party from tampering with and denying the management content.
Beside this, there may be others use case. I'm not sure if Alto servers are
willing to do those work, but it may be helpful to collect or configure some
key information.
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.
It looks that you want to consider both modes: multidomains but single operator
(i.e., intra-cooperation) and multidomains and multiple operators. Regardless,
I agree that it is important for the work to clarify on the privacy
requirements.
[Peng] Yes, agree.
Richard
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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