Network Working Group L. Dunbar
Internet Draft Huawei
Intended status: Informational M. Zarny
Expires: March 2015 Goldman Sachs
C. Jacquenet
France Telecom
S. Chakrabarty
US Ignite
September 25, 2014
Interface to Network Security Functions Problem Statement
draft-dunbar-i2nsf-problem-statement-00.txt
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. This document may not be modified,
and derivative works of it may not be created, except to publish it
as an RFC and to translate it into languages other than English.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other documents
at any time. It is inappropriate to use Internet-Drafts as
reference material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
This Internet-Draft will expire on March 25, 2009.
Dunbar, et al. Expires March 25, 2015 [Page 1]
Internet-Draft I2NSF Problem Statement September 2014
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with
respect to this document. Code Components extracted from this
document must include Simplified BSD License text as described in
Section 4.e of the Trust Legal Provisions and are provided without
warranty as described in the Simplified BSD License.
Abstract
This draft describes the motivation, use cases, and the problem
statement for network security as a service.
Table of Contents
1. Introduction...................................................3
1.1. Motivation................................................3
1.2. Network Security Functions under Consideration............4
1.3. The scope of the proposed work............................5
2. Conventions used in this document..............................7
3. Use Case: Virtual Firewall Function On Demand in Cloud DCs.....8
4. Use Case: Security Functions provided to a Mobile Operator.....9
5. Problem Space.................................................10
5.1. Issues of the current Cloud-based Security Solutions.....10
5.2. Other problems...........................................11
5.3. The Benefits.............................................11
6. Related industry initiatives..................................12
6.1. Related IETF WGs.........................................12
6.2. Relationship with ETSI NFV...............................13
6.3. OpenStack Firewall/Security as a Service.................13
6.4. Security as a Service by Cloud Security Alliance.........14
6.5. Productive Eco-system with Open Source Communities.......14
7. Potential Solutions...........................................14
8. Conclusion and Recommendation.................................15
9. Manageability Considerations..................................15
Dunbar, et al. Expires March 25, 2015 [Page 2]
Internet-Draft I2NSF Problem Statement September 2014
10. Security Considerations......................................15
11. IANA Considerations..........................................15
12. References...................................................16
12.1. Normative References....................................16
12.2. Informative References..................................16
13. Acknowledgments..............................................16
1. Introduction
This draft describes the motivation, use cases, and the problem
statement for Interface to Network Security Functions.
In the context of I2NSF, the term "Virtual Network Security
Function" is used frequently to emphasize the point that the
entities that consume the Network Security functions don't own or
host them. Those network security functions can be achieved by
physical appliances, or by VMs instantiated on servers.
1.1. Motivation
Enterprises are increasingly consuming network functions, especially
the network security related functions that are hosted off their
promises. Some of the reasons driving up this demand are the desire
(and the necessity) to:
. Implement stringent security functions at branch offices where
minimal security infrastructures/capabilities exist;
. Provide virtual network security services for clients, and/or
applications operating over virtual networks in third party
managed (or cloud) data centers;
. Maintain consistent security policies across a large number of
sites, users, or small low powered/low processing sensors.
According to [Gartner-2013], the demand for cloud-based security
services is growing. Small and medium-sized businesses (SMBs) are
increasingly adopting cloud-based security services to replace on-
premises security tools, while larger enterprises are deploying a
mix of traditional and cloud-based security services.
Dunbar, et al. Expires March 25, 2015 [Page 3]
Internet-Draft I2NSF Problem Statement September 2014
To efficiently meet the dynamic demand of security functions
requests from clients, it is desirable to have mechanisms to:
. Create/delete/manage virtual security functions over physical
appliances, (e.g. Dynamically provision and update firewall
policies for a virtual FW instance),
. Have standardized concrete rules (or attributes) for
instantiating VMs for virtual security functions, and
. Have standardized mechanisms for clients, users, or
applications to request/negotiate/validate security functions
that are not physically located on the local premises.
Despite their increasing popularity, most common cloud security
services do not yet have industry standards by which users/clients
can request their desired services. (The "user-provider"
relationship may exist between two different firms or between
different domains of the same firm.)
Another area ripe for standardization is how these services may be
dynamically provisioned, updated, or/and verified to fulfill on-
demand requests. Issues here range from the more typical ones like
the scalability, availability and extensibility of the cloud-based
services to more esoteric ones like a lack of intelligent policy to
configuration translation and a lack of consistent way to implement
policies across multiple regions and entities.
1.2. Network Security Functions under Consideration
There are many network functions being deployed and new ones are
popping up with business and application demands. In order to have a
concrete context for the protocols discussion, we start with the
following network security related functions:
. Firewall
. DDOS/Anti-DOS
. Access control/Authorization/Authentication
. Remote identity management
. Secure Key management
Dunbar, et al. Expires March 25, 2015 [Page 4]
Internet-Draft I2NSF Problem Statement September 2014
. Intrusion Detection System/ Intrusion Prevention System
(IDS/IPS)
The reason for starting with security-related functions is due to
the wide acceptance of security functions that are not running on
customer/enterprise premises. Numerous security vendors are now
leveraging cloud based models to deliver security solutions. This
shift has occurred for a variety of reasons including greater
economies of scale, streamlined delivery mechanisms, and the demand
of business and applications for more sophisticated security
functions that they do not have. Consumers, enterprise clients as
well as applications are embracing the business model of requesting
for security functions that do not run on their own premises on
demand, also known as Network Security as a Service.
1.3. The scope of the proposed work
The Interface to Network Security Functions (I2NSF) initiative aims
at improving the dynamic allocation and operation of network
security functions by documenting a global framework that would
include protocol-based control and management interfaces, along with
adequate data models. The information required for the provisioning,
the configuration and the operation of network security functions
will be exchanged through the said interfaces and protocols. The
I2NSF initiative will also take into account the need for co-
existing with legacy configuration and management systems used to
allocate and operate network security functions, whether they are
embedded in network devices or virtualized in data center
environments, for example. The standard Interface to
request/negotiate/allocate/operate (Virtual) Network Security
Functions (I2NSF) is one of the necessary tools for operators and
service providers to offer network security functions as a service
to their corporate clients.
It is envisioned that clients of the I2NSF interfaces include
management applications, service orchestration systems, network
controllers, or user applications that may solicit network security
resources.
Dunbar, et al. Expires March 25, 2015 [Page 5]
Internet-Draft I2NSF Problem Statement September 2014
Various aspects to I2NSF include:
- The mechanism for clients (applications) to
request/negotiate/validate security functions that are not
physically located on the local premises,
- The mechanism for creating virtual security functions on physical
appliances, and
- Application/user oriented rules/policies to instantiate virtual
security functions as VMs on common compute servers (NFV
initiative).
The "requester <-> provider" relationship has different connotations
in different scenarios:
- Client <-> Provider relationship, i.e. client requesting some
network functions from its provider;
- Inter-domain, e.g. Domain A <-> Domain B relationship, i.e. one
operator domain requesting some network functions from another
operator domain, where "A" and "B" can be from same operator or
different operators; or
- Applications <-> Network relationship, i.e. an application (e.g.
cluster of servers) requesting some functions from network, etc.
The security functions offered by third party need Bi-directional
periodic communications among multiple entities for policies
negotiation, validation, potentially re-directing traffic to higher
level security functions, etc. Therefore, the service requires
programmatic interfaces or protocol exchange, whereas API is
conventionally associated with functional calls on one system.
The objective of the proposed work is to standardize the protocols
(or the interface) and architecture for Requester and Provider to
negotiate the functions needed as well as the associated attributes.
The proposed protocols between requester and provider can be used
for the following scenarios:
Dunbar, et al. Expires March 25, 2015 [Page 6]
Internet-Draft I2NSF Problem Statement September 2014
. A Client requests a certain network security function from a
provider
. The provider fulfills the request for example, by instantiating
an instance of the service in question, or configures an
additional rule in an already provisioned service.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [RFC2119].
In this document, these words will appear with that interpretation
only when in ALL CAPS. Lower case uses of these words are not to be
interpreted as carrying RFC-2119 significance.
Cloud DC: The data centers that are not on premises of enterprises
yet have the compute/storage resources that can be
requested or purchased by the enterprises. What the
enterprises actually get is Virtual Data Centers.
DC: Data Center
Domain: The term "Domain" in this draft has different
connotations in different scenarios:
Client <-> Provider relationship, i.e. client requesting
some network functions from its provider;
Domain A <-> Domain B relationship, i.e. one operator
domain requesting some network functions
from another operator domain; or
Applications <-> Network relationship, i.e. an
application (e.g. cluster of servers)
requesting some functions from network, etc.
Dunbar, et al. Expires March 25, 2015 [Page 7]
Internet-Draft I2NSF Problem Statement September 2014
Virtual Network Function: In the context of I2NSF, the term
"Virtual Network Function" is used frequently to
emphasize the point that the entities that consume the
Network functions, mostly L4-L7 functions, don't own or
host them. Those network functions can be achieved by
physical appliances, or by VMs instantiated on common
compute servers (i.e. the ETSI NFV defined Virtualized
network functions).
Virtual Security Function: a security function that can be requested
by one domain but may be owned or managed by another
domain.
Cloud-based security functions: used interchangeably with the
"Virtual Security Functions" in this draft.
NBI: Northbound Interface. "Northbound" can be ambiguous because
"northbound" to entity A can be southbound to entity B.
So we try to avoid using "northbound" in I2NSF.
3. Use Case: Virtual Firewall Function On Demand in Cloud DCs
Clients of a third party (or cloud) data center not only need
virtual networks to interconnect their virtual compute/storage
resources, but they also need virtual firewall services to enforce
the proper communication policies. VPN clients, especially branch
office access points, may need firewalls that are hosted by the VPN
provider to be integrated with the VPN service.
Per [NW-2011], A cloud-based firewall is different from an on-
premise one (aside from its location) in three key areas:
scalability, availability and extensibility.
. Scalability: Cloud-based firewalls are designed to serve
multiple customers and their increasing demand. Unlike with an
on-premise firewall, upgrading a cloud-based firewall-e.g.,
for greater throughput-should be transparent to enterprise
users.
. Availability: Cloud-based firewall providers tend to offer
extremely high availability through their highly redundant and
Dunbar, et al. Expires March 25, 2015 [Page 8]
Internet-Draft I2NSF Problem Statement September 2014
resilient data centers. In contrast, most enterprises may not
be able to offer "carrier-grade" high availability.
. Extensibility: Enterprises looking for vendor diversity can
subscribe to cloud-based firewalls from different providers.
Furthermore, additional features can be added more seamlessly,
transparently.
4. Use Case: Security Functions provided to a Mobile Operator
Maintaining security is challenging, especially in mobile
environments, where all kinds of user devices (smartphones, pads,
personal assistants, etc.) access applications located in the cloud.
Not only are applications no longer hosted in contained data
centers, (which have a higher chance of encountering various
security threats), but also the mobile devices might not have the
sophisticated processing power or expertise to run up-to-date
security protection functions to guard against rapidly changing
threats.
Evolving threats to mobile networks can affect mobile devices, radio
access networks (RANs), and applications hosted in cloud data
centers.
The trend is to have security functions delivered as a service from
the provider, without requiring on-premise hardware or software
maintenance.
These security services often include authentication (e.g., the
ability to authenticate employees to control the cloud services and
data they have access to), anti-virus, anti-malware/spyware,
intrusion detection, and security event management, among others.
The security function offering can be between different domains of
one operator or between subscribers to providers. Backhaul operators
can offer the security function services to mobile operators.
Security-as-a-Service to mobile environments offers a number of
benefits, including:
. Greater security expertise than typically available to mobile
users,
Dunbar, et al. Expires March 25, 2015 [Page 9]
Internet-Draft I2NSF Problem Statement September 2014
. Flexibility of managing evolving threats
. Ensuring service availability
. Reducing deployment and operational costs
. Effectively organizing groups of apps or users,
. Constant virus definition updates.
5. Problem Space
5.1. Issues of the current Cloud-based Security Solutions
Many vendors already offer Security as a Service in the cloud.
However, all their solutions are proprietary, with different
interfaces and different modes of operation. Some offerings follow a
peer-to-peer model: i.e. requiring clients to peer with vendor
provided functions hosted in the cloud. Some of the functions might
be hosted in data centers geographically far away from the clients
that need the functions, therefore requiring traffic to be hair-
pinned to the remote data centers. A competing model requires
clients to download their desired functions to local devices. In
this model, it is difficult to maintain consistent software updates
across all the devices. Consistency issues can exist across: (1)
multiple regions for a single application; (2) multiple
applications; and/or (3) multiple zones (e.g., between internal and
perimeter zones).
In addition, the current mode of operation for Security as a Service
via a Cloud infrastructure does not have any common
interfaces/mechanisms for clients or applications to verify if the
required functions can fulfill the policies needed by the
clients/applications. There is a lack of user-friendly service
(policy) template.
Dunbar, et al. Expires March 25, 2015 [Page 10]
Internet-Draft I2NSF Problem Statement September 2014
5.2. Other problems
Here are some other problems associated with Security Function on
Demand that might be out of the scope of this proposed WG:
. Diverse security services:
The proposed WG might not be able to cover every possible
security service.
. Scalability:
Not only diverse CPU/memory needed for different security
functions can be difficult to manage, but the solution itself
may have some limits, e.g. maximum number of firewall rules.
. Availability:
The VNF pool is to address the availability of virtualized
network functions.
. Converting policies to vendor-specific configurations
. Dynamic features update
5.3. The Benefits
The goal of the proposed work is to establish an architectural
framework and mechanisms for clients (or one domain) to request
security functions from a network provider (or another domain). The
framework allows the clients to view, request, and/or verify the
security functions/solution offered by different vendors. This
framework can make it easy for a cluster of devices requiring the
similar security policies to have consistent policies across
multiple sites.
The network service providers, with their physical access to a vast
number of enterprises and consumers, are very well positioned to
provide the "Security Function on Demand" platform. The providers
Dunbar, et al. Expires March 25, 2015 [Page 11]
Internet-Draft I2NSF Problem Statement September 2014
can act as security function brokers to their directly connected
domains. They can offer a service catalog and standard mechanisms by
which enterprises (or applications) can query request, or/and verify
the needed security functions.
With the standard protocols for clients to request the needed
security functions, network operators can leverage their current VPN
to enterprises and access to a vast population of end users to offer
a set of consolidated Security solutions. The IETF can play an
instrumental role in defining this common interface and framework
for network operators.
6. Related industry initiatives
6.1. Related IETF WGs
IETF SFC is about mechanism of chaining together service functions;
VNFpool is about the reliability and availability of the virtualized
network functions. But none of them address how service functions
are requested, or how service functions are fulfilled.
Both SFC and VNFpool don't cover in-depth specification (e.g. rules
for the requested FW) for clients to request its needed functions.
In SFC & VNFpool, FW function is a black box, that is treated in
same way as Video Optimization function. SFC/VNFpool don't cover the
negotiation part, e.g. Client needs Rule x/y/z for FW, but the
Provider can only offer x/z.
IETF SACM (Security Assessment and Continuous Monitoring) specifies
the mechanisms to assess end point security. The end points can be
routers, switches, clustered DB, installed piece of software. SACM
is about "How to encode that policy in a manner where assessment can
be automated". For examples:
- a Solaris 10 SPARC or Window 7 system used in a environment
that requires adherence to a policy of Mission Critical
Classified.
- rules like "The maximum password age must be 30 days" and
"The minimum password age must be 1 day"
Dunbar, et al. Expires March 25, 2015 [Page 12]
Internet-Draft I2NSF Problem Statement September 2014
IETF midcom, nsis, pcp, (arguably) SOCKS have done some work that
have some aspects related to or can be used by I2NSF.
6.2. Relationship with ETSI NFV
We believe that the I2NSF is one of the enabling tools for Network
Security as a Service (NSaaS), which is a subset of VNF as a Service
(VNFaaS) specified by ETSI NFV Group Specification Use Cases
[gs_NFV]. The main benefits of virtualized network functions are
increased flexibility to efficiently share the resources, and
decreased setup and management costs. NFV defines the architecture
to pool together many virtual network functions to be managed and
consumed collectively.
NFV, with its heavy representation from service provider side, can
define more detailed service model for VNFaaS and setting
requirement for IETF's narrowly scoped I2NSF interface/protocols.
6.3. OpenStack Firewall/Security as a Service
Open source projects like OpenStack and CloudStack have begun to
tackle the issues but much work remains. The objective of this draft
is to describe the problem set for which future architecture and
solutions can be developed.
OpenStack completed the Firewall as a Service project and specified
the set of APIs for Firewall services:
http://docs.openstack.org/admin-guide-
cloud/content/fwaas_api_abstractions.html
OpenStack has defined the APIs for managing Security Groups:
http://docs.openstack.org/admin-guide-
cloud/content/securitygroup_api_abstractions.html
The attributes defined by OpenStack Firewall/Security as a Service
are very primitive, even though they can be the basis of the
information model for the I2NSF IETF initiative.
Dunbar, et al. Expires March 25, 2015 [Page 13]
Internet-Draft I2NSF Problem Statement September 2014
6.4. Security as a Service by Cloud Security Alliance
https://cloudsecurityalliance.org/research/secaas/#_get-involved
SaaS by CSA is at the initial stage of defining the scope of work.
6.5. Productive Eco-system with Open Source Communities
Open-source initiatives are not to be considered as an alternative
to formal standardization processes. On the contrary, they are
complementary, with the former acting as an enabler and
accelerator of the latter. Open-source provides an ideal mechanism
to quick prototyping and validating contending proposals, and
demonstrating the feasibility of disruptive ideas that could
otherwise not be considered. In this respect, open-source
facilitates the engagement in the standardization process of small
(and typically more dynamic) players such as start-ups and
research groups, that would see better opportunities of being
heard and a clearer rewards to their efforts. An open-source
approach is extremely useful as well for the production of open
reference implementations of the standards at the same (or even
faster) pace they are defined. The availability of such reference
implementations translate into much simpler interoperability and
conformance assessments for both providers and users, and can
become the basis for incremental differentiation of a common
solution, thus allowing a cooperative competition ("coopetition")
model.
7. Potential Solutions
While it is too early to specify any solutions, some potential
candidates are described just to prove that the identified problem
is well bounded for the IETF to specify the needed solutions.
The protocol needed for this negotiation may be somewhat correlated
to the dynamic service parameter negotiation procedure [RFC7297].
The CPP template documented in RFC7297, even though currently
covering only Connectivity, could be extended as a basis for the
negotiation procedure. Likewise, the companion CPNP protocol could
be a candidate to proceed with the negotiation procedure.
Dunbar, et al. Expires March 25, 2015 [Page 14]
Internet-Draft I2NSF Problem Statement September 2014
The "security as a service" would be a typical example of the kind
of (CPP-based) negotiation procedures that could take place between
a corporate customer and a service provider. However, more security
specific parameters have to be considered by this proposed work.
8. Conclusion and Recommendation
The I2NSF aims at documenting a high-level architecture that will
describe the functional building blocks for the dynamic negotiation
of security service parameters, the dynamic and subsequent
allocation of network security resources and the operation of such
resources, including means to assess that what has been allocated
complies with what has been negotiated. The work to be conducted by
the I2NSF WG also includes the documentation of use cases as well as
the specification of information and data models that will provide
the adequate level of abstraction. In addition, the I2NSF WG will
analyze candidate protocols that may carry the information to be
exchanged through the various interfaces (e.g., between a customer
and a service provider, between the control plane and the data
plane, etc.) for the purpose of network security resource
negotiation, allocation and operation.
9. Manageability Considerations
TBD.
10. Security Considerations
TBD
11. IANA Considerations
This document requires no IANA actions. RFC Editor: Please remove
this section before publication.
Dunbar, et al. Expires March 25, 2015 [Page 15]
Internet-Draft I2NSF Problem Statement September 2014
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC7297] Boucadair, M., "IP Connectivity Provisioning Profile",
RFC7297, April 2014.
12.2. Informative References
[gs_NFV] ETSI NFV Group Specification, Network Functions
Virtualizsation (NFV) Use Cases. ETSI GS NFV 001v1.1.1,
2013.
[Boucadair-framework] M. Boucadair, et al, "Differentiated Service
Function Chaining Framework", < draft-boucadair-service-
chaining-framework-00>; Aug 2013
[Gartner-2013] E. Messmer, "Gartner: Cloud-based security as a
service set to take off", Network World, 31 October 2013
[NW-2011] J. Burke, "The Pros and Cons of a Cloud-Based Firewall",
Network World, 11 November 2011
[SC-MobileNetwork] W. Haeffner, N. Leymann, "Network Based Services
in Mobile Network", IETF87 Berlin, July 29, 2013
[Application-SDN] J. Giacomonni, "Application Layer SDN", Layer 123
ONF Presentation, Singapore, June 2013
13. Acknowledgments
Acknowledgements to Andy Malis for his review and contributions.
This document was prepared using 2-Word-v2.0.template.dot.
Dunbar, et al. Expires March 25, 2015 [Page 16]
Internet-Draft I2NSF Problem Statement September 2014
Authors' Addresses
Linda Dunbar
Huawei Technologies
5340 Legacy Drive, Suite 175
Plano, TX 75024, USA
Phone: (469) 277 5840
Email: ldunbar@huawei.com
Myo Zarny
Goldman Sachs
30 Hudson Street
Jersey City, NJ 07302
Email: myo.zarny@gs.com
Christian Jacquenet
France Telecom
Rennes 35000
France
Email: Christian.jacquenet@orange.com
Shaibal Chakrabarty
US Ignite
1776 Massachusetts Ave NW, Suite 601
Washington, DC 20036
Phone: (214) 708 6163
Email: shaibalc@us-ignite.org
Dunbar, et al. Expires March 25, 2015 [Page 17]