I2NSF S. Hares
Internet-Draft L. Dunbar
Intended status: Standards Track Huawei
Expires: June 22, 2016 A. Pastor
D. Lopez
Telefonica I+D
M. Zarny
Goldman Sachs
N. Leymann
Deutsche Telekom
M. Georgiades
Prime Tel
M. Qi
China Mobile
M. Boucadair
C. Jacquenet
France Telecom
S. Chakrabarty
US Ignite
December 20, 2015
I2NSF Problem Statement and Use cases
draft-hares-i2nsf-merged-problem-use-cases-00.txt
Abstract
This document describes the problem statement for Interface to
Network Security Functions (I2NSF) and summary of the I2NSF use
cases.
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This Internet-Draft will expire on June 22, 2016.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Problem Space . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Facing Security Service Providers . . . . . . . . . . . . 5
3.1.1. Diverse Types of Security Functions . . . . . . . . . 5
3.1.2. Diverse Interfaces to Control NSFS . . . . . . . . . 6
3.1.3. Diverse Interface to monitor the behavior of NSFs . . 7
3.1.4. More Distributed NSFs and vNSFs . . . . . . . . . . . 7
3.1.5. More Demand to Control NSFs Dynamically . . . . . . . 7
3.1.6. Demand for multi-tenancy to control and monitor NSFs 7
3.1.7. Lack of Characterization of NSFs and Capability
Exchange . . . . . . . . . . . . . . . . . . . . . . 7
3.1.8. Lack of Mechanism for NSFs to utilize external
profiles . . . . . . . . . . . . . . . . . . . . . . 8
3.1.9. Lack of Mechanisms to accept external alerts to
trigger automatic configuration changes . . . . . . . 8
3.1.10. Lack of mechanism for dynamic key distribution to
NSFs . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2. Challenges Facing Customers . . . . . . . . . . . . . . . 10
3.2.1. NSFs from Heterogeneous Administrative Domains . . . 10
3.2.2. Today's Control Requests are Vendor Specific . . . . 11
3.2.3. Difficulty to Monitor the Execution of Desired
Policies . . . . . . . . . . . . . . . . . . . . . . 12
3.3. Difficulty to Validate Policies across Multiple Domains . 13
3.4. Lack of Standard Interface to Inject Feedback to NSF . . 13
3.5. Lack of Standard Interface for Capability Negotiation . . 13
4. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1. General Use Cases . . . . . . . . . . . . . . . . . . . . 14
4.2. Access Networks . . . . . . . . . . . . . . . . . . . . . 15
4.3. Cloud Datacenter Scenario . . . . . . . . . . . . . . . . 17
4.3.1. On-Demand Virtual Firewall Deployment . . . . . . . . 17
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4.3.2. Firewall Policy Deployment Automation . . . . . . . . 18
4.3.3. Client-Specific Security Policy in Cloud VPNs . . . . 18
4.3.4. Internal network monitoring . . . . . . . . . . . . . 19
5. Management Considerations . . . . . . . . . . . . . . . . . . 19
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
7. Security Considerations . . . . . . . . . . . . . . . . . . . 19
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 19
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
9.1. Normative References . . . . . . . . . . . . . . . . . . 19
9.2. Informative References . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction
This document describes the problem statement for Interface to
Network Security Functions (I2NSF) and summary of the I2NSF use
cases. A summary of the I2NSF state of the art in the industries and
IETF which is relevant to I2NSF work is contained in
[I-D.hares-i2nsf-gap-analysis].
The growing challenges and complexity in maintaining a secure
infrastructure, complying with regulatory requirements, and
controlling costs are enticing enterprises into consuming network
security functions hosted by service providers. The hosted security
service is especially attractive to small and medium size enterprises
who suffer from a lack of security experts to continuously monitor,
acquire new skills and propose immediate mitigations to ever
increasing sets of security attacks.
According to [Gartner-2013], the demand for hosted (or 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.
To meet the demand, more and more service providers are providing
hosted security solutions to deliver cost-effective managed security
services to enterprise customers. The hosted security services are
primarily targeted at enterprises (especially small/medium ones), but
could also be provided to any kind of mass-market customer. As the
result, the Network security functions (NSFs) are provided and
consumed in increasingly diverse environments. Users of NSFs may
consume network security services hosted by one or more providers,
which may be their own enterprise, service providers, or a
combination of both. This document also briefly describes the
following use cases summarized by
[I-D.pastor-i2nsf-merged-use-cases]:
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o [I-D.pastor-i2nsf-access-usecases] (I2NSF-Access),
o [I-D.zarny-i2nsf-data-center-use-cases](I2NSF-DC), and
o [I-D.qi-i2nsf-access-network-usecase] (I2NSF-Mobile).
2. Terminology
ACL: Access Control List
B2B: Business-to-Business
Bespoke: Something made to fit a particular person, client or
company.
Bespoke security management: Security management which is make to
fit a particular customer.
DC: Data Center
FW: Firewall
IDS: Intrusion Detection System
IPS: Intrusion Protection System
NSF: Network security function. An NSF is a function that that
detects unwanted activity and blocks/mitigates the effect of such
unwanted activity in order to support availability of a network.
In addition, the NSF can help in supporting communication stream
integrity and confidentiality.
Flow-based NSF: A NSF which inspects network flows according to a
policy intended for enforcing security properties. Flow based
security also means that packets are inspected in the order they
are received, and without modification to the packet due to the
inspection process (MAC rewrites, TTL decrement action, or NAT
inspection or changes).
Virtual NSF: A NSF which is deployed as a distributed virtual
device.
VNFPool: Pool of Virtual Network Functions.
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3. Problem Space
The following sub-section describe the problems and challenges facing
customers and security service providers when some or all of the
security functions are no longer physical hosted by the customer's
administrative domain.
Security service providers can be internal to the company or external
security service providers. For example, an internal IT Security
group within a large enterprise could act as a security service
provider for the enterprise. In contrast, an enterprise could
outsource all security services to an external security service
provider in a global service provider. In document, the security
service provider function whether it is internal or external, will be
denoted as "service provider".
The "Customer-Provider" relationship may be between any two parties.
The parties can be in different firms or different domains of the
same firm. Contractual agreements may be required in such contexts
to formally document the customer's security requirements and the
provider's guarantees to fulfill those requirements. Such agreements
may detail protection levels, escalation procedure, alarms reporting,
etc. There is currently no standard mechanism to capture those
requirements.
A service provider may be a customer of another service provider.
3.1. Facing Security Service Providers
3.1.1. Diverse Types of Security Functions
There are many types of NSFs. NSFs by different vendors can have
different features and have different interfaces. NSFs can be
deployed in multiple locations in a given network, and perhaps have
different roles.
Below are a few examples of security functions and locations or
contexts in which they are often deployed:
External Intrusion and Attack Protection: Examples of this function
are firewall/ACL authentication, IPS, IDS, and endpoint
protection.
Security Functions in a DMZ: Examples of this function are
firewall/ACLs, IDS/IPS, authentication and authorization services,
NAT, forwarding proxies, application, and AAA services. These
functions may be physically on-premise in a server provider's
network at the DMZ spots or at "virtual" DMZ.
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Internal Security Analysis and Reporting: Examples of this function
are security logs, event correlation, and forensic analysis.
Internal Data and Content Protection: Examples of this function are
encryption, authorization, and public/private key management for
internal database.
Given the diversity of security functions, the contexts in which
these functions can be deployed, and the constant evolution of these
functions, standardizing all aspects of security functions is
challenging, and most probably not feasible. Fortunately, it is not
necessary to standardize all aspects. For example, from an I2NSF
perspective, there is no need to standardize on how a firewall
filters are created or applied.
What is needed is having a standardized interface to control and
monitor the rule sets that NSFs use to treat packets traversing
through. And standardizing interfaces will provide an impetuous for
standardizing established security functions.
3.1.2. Diverse Interfaces to Control NSFS
To provide effective and competitive solutions and services, Security
Service Providers may need to utilize multiple security functions
from various vendors to enforce the security policies desired by
their customers.
Since no widely accepted industry standard security interfaces exists
today, management of NSFs (device and policy provisioning,
monitoring, etc.) tends to be bespoke security management offered by
product vendors. As a result, automation of such services, if it
exists at all, is also bespoke. Thus, even in the traditional way of
deploying security features, there is a gap to coordinate among
implementations from distinct vendors. This is the main reason why
mono-vendor security functions are often deployed and enable in a
particular network segment.
A challenge for monitoring is that an NSF cannot monitor what it
cannot view. Therefore, enabling a security function (e.g., firewall
[I-D.ietf-opsawg-firewalls]) does not mean that a network is
protected. As such, it is necessary to have a mechanism to monitor
and provide execution status of NSFs to security and compliance
management tools. There exist various network security monitoring
vendor specific interfaces for forensics and troubleshooting.
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3.1.3. Diverse Interface to monitor the behavior of NSFs
Obviously, enabling a security function (e.g., firewall
[I-D.ietf-opsawg-firewalls] does not mean that a network is
protected. Therefore, it is necessary to have a mechanism to monitor
the execution status of NSFs.
3.1.4. More Distributed NSFs and vNSFs
The security functions which are invoked to enforce a security policy
can be located in different equipment and network locations.
The European Telecommunications Standards Institute (ETSI) Network
Function Virtualization (NFV) initiative creates new management
challenges for security policies to be enforced by distributed,
virtual, and network security functions (vNSF).
A vNSF has higher risk of failure, migrating, and state changes as
their hosting VMs being created, moved, or decommissioned.
3.1.5. More Demand to Control NSFs Dynamically
In the advent of SDN (see [I-D.jeong-i2nsf-sdn-security-services]),
more clients, applications or application controllers need to
dynamically update their communication policies that are enforced by
NSFs. The Security Service Providers have to dynamically update
control requests to NSFs upon receiving the requests from their
clients
3.1.6. Demand for multi-tenancy to control and monitor NSFs
Service providers may require having several operational units to
control and monitor the NSFs, especially when NSFs become distributed
and virtualized.
3.1.7. Lack of Characterization of NSFs and Capability Exchange
To offer effective security services, service providers need to
activate various security functions in NSFs or vNSFs manufactured by
multiple vendors. Even within one product category (e.g., firewall),
security functions provided by different vendors can have different
features and capabilities. For example, filters that can be designed
and activated by a firewall may or may not support IPv6 depending on
the firewall technology.
The service provider's management system (or controller) needs a way
to retrieve the capabilities of service functions by different
vendors so that it could build an effective security solution. These
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service function capabilities can be documented in a static manner
(e.g. a file) or via an interface which access a repository of
security function capabilities which the NSF vendors dynamically
update.
A dynamic capability registration is useful for automation because
security functions may be subject to software and hardware updates.
These updates may have implications on the policies enforced by the
NSFs.
Today, there is no standard method for vendors to describe the
capabilities of their security functions. Without a common technical
framework to describe the capabilities of security functions, service
providers cannot automate the process of selecting NSFs by different
vendors to accommodate customer's requirements.
3.1.8. Lack of Mechanism for NSFs to utilize external profiles
Many security functions depend on signature files or profiles to
perform (e.g. IPS/IDS signatures, DOTS filters). Different policies
might need different signatures or profiles. Today, the construction
and use of black databases can be win-win strategy for all parties
involved. There might be Open Source provided signature/profiles
(e.g. by Snort or others) in the future.
There is a need to have a standard envelop (i.e. the format) to allow
NSFs to use external profiles.
3.1.9. Lack of Mechanisms to accept external alerts to trigger
automatic configuration changes
NSF can ask the I2NSF security controller to alter network policy.
For example, a DDoS alert could trigger a change to routing system to
send traffic to a traffic scrubbing service to mitigate the DDoS.
The DDoS protection has the following two parts: a) the configuration
of signaling of open threats and b) DDoS mitigation. DOTS controller
manages the signaling part of DDoS. I2NSF controller(s) would manage
the changing to the network policy. By monitoring the network alerts
from DDoS, I2NSF can feed a alerts analytics engine that could
recognize attacks and the I2NSF can implement the needed new
policies.
DDoS mitigation is enhanced if the provider's network security
controller can monitor, analyze, and investigate the abnormal events
and provide information to the client or change the network
configuration (see section x) for details on the interfaces.
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[I-D.zhou-i2nsf-capability-interface-monitoring] provides details on
how monitoring aspects of the flow-based Network Security Functions
(NSFs) can use the I2NSF interfaces to receive traffic reports and
enforce policy.
3.1.10. Lack of mechanism for dynamic key distribution to NSFs
There is a need for controller to distribute various keys to
distributed NSFs. To distribute various keys, the keys must be
created and managed. While there is many key management methods and
key derivation functions (KDF), there is a lack of standard interface
to provision and manage keys.
The keys may be used for message authentication and integrity in
order to protect data flow. In addition, keys may be used to secure
the protocol and messages in the core routing infrastructure.
As of now there is no much focus on an abstraction for keying
information that describes the interface between protocols,
operators, and automated key management.
The keys may be used for message authentication and integrity in
order to protect data flow. In addition, keys may be used to secure
the protocol and messages in the core routing infrastructure.
The ability to utilize keys when routing protocols send or receive
messages will be enhanced by having an abstract key table maintained
by a security services. Conceptually, there must be an interface
defined for routing/signaling protocols to make requests of automated
key management when it is being used, to notify the protocols when
keys become available in the key table.
An abstract key service needs to have three things:
1. I2NSF need to design the key table abstraction, the interface
between key management protocols and routing/other protocols, and
possibly security protocols at other layers.
2. For each routing/other protocol, I2NSF need to define the mapping
between how the protocol represents key material and the
protocol-independent key table abstraction. (If protocols share
common mechanisms for authentication (e.g. TCP Authentication
Option), then the same mapping may be reused.)
3. Automated Key management must support both symmetric keys and
group keys via the service provided by items 1 and 2.
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3.1.10.1. Background on Core Routing Security
A recommendation from a workshop held by the Internet Architecture
Board (IAB) held a workshop on the topic of "Unwanted Internet
Traffic" [RFC4948] suggest since a "simple risk analysis" suggests an
"ideal attack target of minimal cost but maximal disruption is the
core routing infrastructure", it is important to "tightening the
security of the core routing infrastructure". One of the ways to
tighten security of the core routing infrastructure is to tighten the
security of protocol packets on the wire is by protecting the
messages by use of keys.
Conceptually, when routing protocols send or receive messages, they
might need to look up the key to use in this abstract key table.
Conceptually, there must be an interface defined for a protocols to
make requests of automated key management when it is being used; when
keys become available, they might be made available in the key table.
3.2. Challenges Facing Customers
When customers invoke hosted security services, their security
policies may be enforced by a collection of security functions hosted
in different domains. Customers may not have the security skills to
express sufficiently precise requirements or security policies.
Usually these customers express the expectations of their security
requirements or the intent of their security policies. These
expectations can be considered customer level security expectations.
Customers may also desire to express guidelines for security
management. Examples of such guidelines are the following:
o Which critical communications are to be preserved during critical
events (DOTS),
o Which hosts are to continue service even during severe security
attacks (DOTS),
o Reporting of attacks to CERT (MILE),
o Managing network connectivity of systems out of compliance (SACM),
3.2.1. NSFs from Heterogeneous Administrative Domains
Many medium and large enterprises have deployed various on-premises
security functions which they want to continue to deploy. These
enterprises want to combine local security functions with remote
hosted security functions to achieve more efficient and immediate
counter-measures to both Internet-originated attacks and enterprise
network-originated attacks.
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Some enterprises may only need the hosted security services for their
remote branch offices where minimal security infrastructures/
capabilities exist. The security solution will consist of NSFs on
customer networks and NSFs on service provider networks.
3.2.2. Today's Control Requests are Vendor Specific
Customers may consume NSFs by multiple service providers. Customers
need to express their security requirements, guidelines, and
expectations to the service providers. In turn, the service
providers must translate this customer information into customer
security policies and associated configuration sets for the set of
security functions in their network. Without a standard technical
characterizations or a standard interface, the service provide faces
many challenges.
Due the lack of standard technical characterizations and a standard
interfaces, the following problems exists:
No standard technical characterization and/or APIs : Even the most
common security services there is no standard technical
characterization or APIs. Most security services are accessible
only through disparate, proprietary interfaces (e.g., portals or
APIs) in whatever format vendors choose to offer. The service
provider must the customer's input to these widely varying
interfaces.
No standard interface: Without standard interfaces it is complex
for customers to update security policies or integrate the
security functions in their enterprise with the security services
provided by the security service providers. This complexity is
induced by the diversity of the configuration models, policy
models, and supported management interfaces. Without a standard
interface, new innovative security products find a large barrier
to entry into the market
Managing by scripts de-jour: The current practices rely on the use
of scripts which generate other scripts which the automatically
run to upload or download configuration changes, log information
and other things. These scripts have to be adjusted each time an
implementation from a different vendor is enabled in a provider
side.
Lack of immediate Feedback: Customers may also require a mechanism
to easily update/modify their security requirements with immediate
effect in the underlying involved NSFs.
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Lack of explicit invocation request: While security agreements are
in place, security functions may be solicited without requiring an
explicit invocation means. Nevertheless, some explicit invocation
means may be required to interact with a service function.
To see how standard interfaces could help achieve faster
implementation time cycles, let us consider a customer who would like
to dynamically allow an encrypted flow with specific port, src/dst
addresses or protocol type through the firewall/IPS to enable an
encrypted video conferencing call only during the time of the call.
With no commonly accepted interface in place, the customer would have
to learn about the particular provider's firewall/IPS interface and
send the request in the provider's required format.
+------------+
| security |
| MGT system |
+----||------+
|| proprietary
|| or I2NSF standard
Picture: ||
Port 10 +--------+
--------| FW/IPS |-------------
Encrypted +--------+
Video Flow
Figure 2: Example of non-standard vs. standard interface
In contrast, if a firewall/IPS interface standard exists, the
customer would be able to send the request, without having to do the
extensive preliminary legwork. A standard interface also helps
service providers since they could now offer the same firewall/IPS
interface to represent firewall/IPS services for utilizing products
from many vendors. The result is that the service provider has now
abstracted the firewall/IPS services. The standard interface also
helps the firewall/IPS vendors to focus on their core security
functions or extended features rather than the standard building
blocks of a management interface.
3.2.3. Difficulty to Monitor the Execution of Desired Policies
How a policy is translated into technology-specific actions is hidden
from the customers. However, customers still need ways to monitor
the delivered security service that results from the execution of
their desired security requirements, guidelines and expectations.
Today, there is no standard way for customers to get security service
assurance of their specified security policies properly enforced by
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the security functions in the provider domain. The customer also
lacks the ability to perform "what-if" scenarios to assess the
efficiency of the delivered security service.
3.3. Difficulty to Validate Policies across Multiple Domains
One key aspect of a hosted security service with security functions
located at different premises is the ability to express, monitor and
verify security policies that combine several distributed security
functions. It is crucial to an effective service to be able to take
these actions via a standard interface. This standard interface
becomes more crucial to the hosted security service when NSFs are
instantiated in Virtual Machines which are sometimes widely
distributed in the network and sometimes are combined together in one
device to perform a set of asks in a service.
Without standard interfaces and security policy data models, the
enforcement of a customer-driven security policy remains challenging
because of the inherent complexity created by the combining the
invocation of several vendor-specific security functions into a
multi-vendor, heterogeneous environment. Each vendor specific
function may require specific configuration procedures and
operational tasks.
Ensuring the consistent enforcement of the policies at various
domains is also challenging. Standard data models are likely to
contribute to ameliorating that issue.
3.4. Lack of Standard Interface to Inject Feedback to NSF
Today, many security functions, such as IPS, IDS, DDoS and Antivirus,
depend heavily on the associated profiles. They can perform more
effective protection if they have the up-to-date profiles. As more
sophisticated threats arise, enterprises, vendors, and service
providers have to rely on each other to achieve optimal protection.
Cyper Threat Alliance (CA, http://cyberthreatalliance.org/) is is one
of those initiatives that aim at combining efforts conducted by
multiple organizations.
Today there is no standard interface to exchange security profiles
between organizations.
3.5. Lack of Standard Interface for Capability Negotiation
There could be situations when the NSFs selected cannot perform the
policies requested by the Security Controller, due to resource
constraints. To support the automatic control in the SDN-era, it is
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necessary to have a set of messages for proper negotiation between
the Security Controller and the NSFs.
4. Use Cases
Standard interfaces for monitoring and controlling the behavior of
NSFs are essential building blocks for Security Service Providers and
enterprises to automate the use of different NSFs from multiple
vendors by their Security management entities. I2NSF may be invoked
by any (authorized) client. Examples of authorized clients are
upstream applications (controllers), orchestration systems, and
security portals.
4.1. General Use Cases
User request security services through specific clients (e.g. a
customer application, the NSP BSS/OSS or management platform) and the
appropriate NSP network entity will invoke the (v)NSFs according to
the user service request. We will call this network entity the
security controller. The interaction between the entities discussed
above (client, security controller, NSF) is shown in the following
diagram:
+----------+
+-------+ | | +-------+
| | Interface 1 |Security | Interface 2 | NSF(s)|
|Client <-------------> <------------------> |
| | |Controller| | |
+-------+ | | +-------+
+----------+
Figure 2: Interaction between Entities
Interface 1 is used for receiving security requirements from client
and translating them into commands that NSFs can understand and
execute. The security controller also passes back NSF security
reports (e.g. statistics) to the client which the control has
gathered from NSFs. Interface 2 is used for interacting with NSFs
according to commands, and collect status information about NSFs.
Client devices or applications can require the security controller to
add, delete or update rules in the security service function for
their specific traffic.
When users want to get the executing status of security service, they
can request the information of NSFs from the client. The security
controller will collect NSF information through Interface 2,
consolidate them, and give feedback to client through Interface 1.
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This interface can be used to collect not only individual service
information, but also aggregated data suitable for tasks like
infrastructure security assessment.
Customers may require validating NSF availability, provenance, and
correct execution. This validation process, especially relevant for
vNSFs, includes at least:
Integrity of the NSF: by ensuring that the NSF is not compromised;
Isolation: by ensuring the execution of the NSF is self-contained
for privacy requirements in multi-tenancy scenarios.
In order to achieve this, the security controller may collect
security measurements and share them with an independent and trusted
third party (via the interface 1) in order to allow for attestation
of NSF functions using the third party added information.
4.2. Access Networks
This scenario describes use cases for users (e.g. enterprise user,
network administrator, and residential user) that request and manage
security services hosted in the network service provider (NSP)
infrastructure. Given that NSP customers are essentially users of
their access networks, the scenario is essentially associated with
their characteristics, as well as with the use of vNSFs.
The Virtual CPE described in [NFVUC] use cases #5 and #7 requires a
model of access virtualization that includes mobile and residential
access where the operator may offload security services from the
customer local environment (E.g. device or terminal) to the operator
infrastructure supporting the access network.
These use cases defines the operator interaction with vNSFs through
automated interfaces, typically by B2B communications.
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Customer + Access + PoP/Datacenter
| | +--------+
| ,-----+--. |Network |
| ,' | `-|Operator|
+-------------+ | /+----+ | |Mgmt Sys|
| Residential |-+------/-+vCPE+----+ +--------+
+-------------+ | / +----+ | \ | :
| / | \ | |
+-------+ | ; +----+ | +----+ |
| Cloud |---+---+----+ vPE+--+----+ NSF| |
+-------+ | : +----+ | +----+ |
| : | / |
+--------+ | : +----+ | / ;
| Mobile |-+-----\--+vEPC+----+ /
+--------+ | \ +----+ | ,-'
| `--. | _.-'
| `----+----''
+ +
Figure 3: NSF and actors
The following are actions required for this access use case:
vNSF Deployment: The deployment process consists of instantiating a
NSF on a Virtualization Infrastructure (NFVI), within the NSP
administrative domain(s) or with other external domain(s). This
is a required step before a customer can subscribe to a security
service supported in the vNSF.
vNSF Customer Provisioning: Once a vNSF is deployed, any customer
can subscribe to it. The provisioning lifecycle includes the
following:
* Customer enrollment and cancellation of the subscription to a
vNSF;
* Configuration of the vNSF, based on specific configurations, or
derived from common security policies defined by the NSP.
* Retrieve and list of the vNSF functionalities, extracted from a
manifest or a descriptor. The NSP management systems can
demand this information to offer detailed information through
the commercial channels to the customer.
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4.3. Cloud Datacenter Scenario
In a datacenter, network security mechanisms such as firewalls may
need to be added or removed dynamically for a number of reasons.
These changes may be explicitly requested by the user, or triggered
by a pre-agreed upon service level agreement (SLA) between the user
and the provider of the service. For example, the service provider
may be required to add more firewall capacity within a set timeframe
whenever the bandwidth utilization hits a certain threshold for a
specified period. This capacity expansion could result in adding new
instances of firewalls on existing machines or provisioning a
completely new firewall instance in a different machine.
The on-demand, dynamic nature of deployment essentially requires that
the network security "devices" be in software or virtual form
factors, rather than in a physical appliance form. This requirement
is a provider-side concern. Users of the firewall service are
agnostic (as they should) as to whether or not the firewall service
is run on a VM or any other form factor. Indeed, they may not even
be aware that their traffic traverses firewalls.
Furthermore, new firewall instances need to be placed in the "right
zone" (domain). The issue applies not only to multi-tenant
environments where getting the tenant in the right domain is of
paramount importance, but also in environments owned and operated by
a single organization with its own service segregation policies. For
example, an enterprise may mandate that firewalls serving Internet
traffic and business-to-business (B2B) traffic be separate. Another
example is that IPS/IDS services for investment banking and non-
banking traffic may be need to separated for regulatory reasons.
4.3.1. On-Demand Virtual Firewall Deployment
A service provider operated cloud data center could serve tens of
thousands of clients. Clients' compute servers are typically hosted
on virtual machines (VMs), which could be deployed across different
server racks located in different parts of the data center. Often it
is not technically and/or financially feasible to deploy dedicated
physical firewalls to suit each client's myriad security policy
requirements. What is needed is the ability to dynamically deploy
virtual firewalls for each client's set of servers based on
established security policies and underlying network topologies.
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---+-----------------------------+-----
| |
+---+ +-+-+
|vFW| |vFW|
+---+ +-+-+
| Client #1 | Client #2
---+-------+--- ---+-------+---
+-+-+ +-+-+ +-+-+ +-+-+
|vM | |vM | |vM | |vM |
+---+ +---+ +---+ +---+
Figure 4: NSF in Data Center
4.3.2. Firewall Policy Deployment Automation
Firewall rules setting is often a time consuming, complex and error-
prone process even within a single organization/enterprise framework.
It becomes far more complex in provider-owned cloud networks that
serve myriad customers.
Firewall rules today are highly tied with ports and addresses of the
traffic. This makes it very difficult for clients of cloud data
center to construct rules for their own traffic as the clients only
see the virtual networks and the virtual addresses. The customer-
visible virtual networks and addresses may be different from the
actual packets traversing the FWs.
Even though most vendors support similar firewall features, the
actual rule configuration key words are different from vendors to
vendors, making it difficult for automation. Automation works best
when it can leverage a common set of standards that will work across
NSFs by multiple vendors. Without automation, it is virtually
impossible for clients to dynamically specify their desired rules for
their traffic.
4.3.3. Client-Specific Security Policy in Cloud VPNs
Clients of service provider operated cloud data centers need not only
secure virtual private networks (VPNs) but also virtual security
functions that enforce the clients' security policies. The security
policies may govern communication within the clients' own virtual
networks as well as communication with external networks. For
example, VPN service providers may need to provide firewall and other
security services to their VPN clients. Today, it is generally not
possible for clients to dynamically view (much less change) what,
where and how security policies are implemented on their provider-
operated clouds. Indeed, no standards-based framework that allows
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clients to retrieve/manage security policies in a consistent manner
across different providers exists.
4.3.4. Internal network monitoring
There are many types of internal traffic monitors that may be managed
by a security controller. This includes a new class of services
referred to as DLP, Data Loss Prevention, or Reputation Protection
Services. Depending on the class of event, alerts may go to internal
administrators, or external services.
5. Management Considerations
Management of NSFs usually include configuration of devices,
signaling and policy provisioning. I2NSF will only focus on the
policy provisioning part.
6. IANA Considerations
No IANA considerations exist for this document.
7. Security Considerations
Having a secure access to control and monitor NSFs is crucial for
hosted security service. The new NSF security controller introduces
a new attack surface. It needs to be resilient to attack and
recovery from attack needs to be quick and trivial (thus making
attacking it 'uninteresting'). Therefore, proper secure
communication channels have to be carefully specified for carrying
the controlling and monitoring information between the NSFs and their
management entity (or entities).
8. Contributors
I2NSF is a group effort. The following people contributed actively
to the initial use case text: Diego R. Lopez (Telefonica I+D),
Xiaojun Zhuang (China Mobile), Minpeng Qi (China Mobile), Sumandra
Majee (F5), Nic Leymann (Deutsche Telekom), Ed Lopez (Fortinet), and
Robert Moskowitz (Huawei).
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
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9.2. Informative References
[Gartner-2013]
Messmer, E., "Gartner: Cloud-based security as a service
set to take off", October 2013.
[I-D.hares-i2nsf-gap-analysis]
Hares, S., Zhang, D., Moskowitz, R., and H. Rafiee,
"Analysis of Existing work for I2NSF", draft-hares-i2nsf-
gap-analysis-00 (work in progress), July 2015.
[I-D.ietf-netmod-acl-model]
Bogdanovic, D., Koushik, K., Huang, L., and D. Blair,
"Network Access Control List (ACL) YANG Data Model",
draft-ietf-netmod-acl-model-06 (work in progress),
December 2015.
[I-D.ietf-opsawg-firewalls]
Baker, F. and P. Hoffman, "On Firewalls in Internet
Security", draft-ietf-opsawg-firewalls-01 (work in
progress), October 2012.
[I-D.jeong-i2nsf-sdn-security-services]
Jeong, J., Kim, H., and P. Jung-Soo, "Requirements for
Security Services based on Software-Defined Networking",
draft-jeong-i2nsf-sdn-security-services-01 (work in
progress), March 2015.
[I-D.lopez-i2nsf-packet]
Ed, E., "Packet-Based Paradigm For Interfaces To NSFs",
draft-lopez-i2nsf-packet-00 (work in progress), March
2015.
[I-D.pastor-i2nsf-access-usecases]
Pastor, A. and D. Lopez, "Access Use Cases for an Open OAM
Interface to Virtualized Security Services", draft-pastor-
i2nsf-access-usecases-00 (work in progress), October 2014.
[I-D.pastor-i2nsf-merged-use-cases]
Pastor, A., Lopez, D., Wang, K., Zhuang, X., Qi, M.,
Zarny, M., Majee, S., Leymann, N., Dunbar, L., and M.
Georgiades, "Use Cases and Requirements for an Interface
to Network Security Functions", draft-pastor-i2nsf-merged-
use-cases-00 (work in progress), June 2015.
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[I-D.qi-i2nsf-access-network-usecase]
Wang, K. and X. Zhuang, "Integrated Security with Access
Network Use Case", draft-qi-i2nsf-access-network-
usecase-02 (work in progress), March 2015.
[I-D.zarny-i2nsf-data-center-use-cases]
Zarny, M., Leymann, N., and L. Dunbar, "I2NSF Data Center
Use Cases", draft-zarny-i2nsf-data-center-use-cases-00
(work in progress), October 2014.
[I-D.zhou-i2nsf-capability-interface-monitoring]
Zhou, C., Xia, L., Boucadair, M., and J. Xiong, "The
Capability Interface for Monitoring Network Security
Functions (NSF) in I2NSF", draft-zhou-i2nsf-capability-
interface-monitoring-00 (work in progress), October 2015.
[RFC4948] Andersson, L., Davies, E., and L. Zhang, "Report from the
IAB workshop on Unwanted Traffic March 9-10, 2006",
RFC 4948, DOI 10.17487/RFC4948, August 2007,
<http://www.rfc-editor.org/info/rfc4948>.
[RFC7277] Bjorklund, M., "A YANG Data Model for IP Management",
RFC 7277, DOI 10.17487/RFC7277, June 2014,
<http://www.rfc-editor.org/info/rfc7277>.
Authors' Addresses
Susan Hares
Huawei
7453 Hickory Hill
Saline, MI 48176
USA
Phone: +1-734-604-0332
Email: shares@ndzh.com
Linda Dunbar
Huawei
5340 Legacy Drive, Suite 175
Plano, TX 75024
USA
Phone: +1-734-604-0332
Email: ldunbar@huawei.com
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Antonio Pastor
Telefonica I+D
Don Ramon de la Cruz, 82
Madrid 28006
Spain
Email: antonio.pastorperales@telefonica.com
Diego R. Lopez
Telefonica I+D
Don Ramon de la Cruz, 82
Madrid 28006
Spain
Phone: +34 913 129 041
Email: diego.r.lopez@telefonica.com
Myo Zarny
Goldman Sachs
30 Hudson Street
Jersey City, NJ 07302
USA
Email: myo.zarny@gs.com
Nic Leymann
Deutsche Telekom
Email: N.Leymann@telekom.de
Michael Georgiades
Prime Tel
Email: michaelq@prime-tel.com
Minpeng Qi
China Mobile
32 Xuanwumenxi Ave,Xicheng District
Beijing 100053
China
Email: qiminpeng@chinamobile.com
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Mohamed Boucadair
France Telecom
Rennes, 35000
France
Email: mohamed.boucadair@orange.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
USA
Phone: (214) 708-6163
Email: shaibalc@us-ignite.org
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