Internet DRAFT - draft-merged-i2nsf-framework
draft-merged-i2nsf-framework
Network Working Group E. Lopez
Internet Draft Fortinet
Intended status: Informational D. Lopez
Expires: September 2016 Telefonica
L. Dunbar
J. Strassner
Huawei
X. Zhuang
China Mobile
J. Parrott
BT
R Krishnan
Dell
S. Durbha
CableLabs
March 16, 2016
Framework for Interface to Network Security Functions
draft-merged-i2nsf-framework-05.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."
xxx, et al. Expires September 16, 2016 [Page 1]
Internet-Draft I2NSF Framework March 2016
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 September 16, 2016.
Copyright Notice
Copyright (c) 2016 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 document defines the framework for guiding the functionality
provided by I2NSF. Network security functions (NSFs) are packet-
processing engines that inspect and optionally modify packets
traversing networks, either directly or in the context of sessions
in which the packet is associated. This document provides an
overview of how NSFs are used, and describes how NSF software
interfaces are controlled and monitored using rulesets. The design
of these software interfaces must prevent the creation of implied
constraints on NSF capability and functionality.
Table of Contents
1. Introduction...................................................3
2. Conventions used in this document..............................4
3. Interfaces to Flow-based NSFs..................................4
xxx, et al. Expires September 16, 2016 [Page 2]
Internet-Draft I2NSF Framework March 2016
4. Reference Models in Managing Flow-based NSFs...................7
4.1. NSF Facing (Capability Layer) Interface...................8
4.2. Client Facing (Service Layer) Interface...................9
4.3. Vendor Facing Interface...................................9
4.4. The Network Connecting the Security Controller and NSFs...9
4.5. Interface to vNSFs.......................................10
5. Flow-based NSF Capability Characterization....................11
6. Structure of Rules for governing NSFs.........................15
6.1. Capability Layer Rules and Monitoring....................15
6.2. Service Layer Policy.....................................16
7. Capability Negotiation........................................19
8. Types of I2NSF clients........................................19
9. Manageability Considerations..................................20
10. Security Considerations......................................20
11. IANA Considerations..........................................20
12. References...................................................21
12.1. Normative References....................................21
12.2. Informative References..................................21
13. Acknowledgments..............................................22
1. Introduction
This document describes the framework for the Interface to Network
Security Functions (I2NSF), and defines a reference model (including
major functional components) for I2NSF. It also describes how I2NSF
facilitates Software-Defined Networking (SDN) and Network Function
Virtualization (NVF) control, while avoiding potential constraints
that could limit the internal functionality and capabilities of
NSFs.
The I2NSF use cases ([I2NSF-ACCESS], [I2NSF-DC] and [I2NSF-Mobile])
call for standard interfaces for clients (e.g., applications,
application controllers, or users), to inform the network what they
are willing to receive. I2NSF realizes this as a set of security
rules for monitoring and controlling the behavior of their specific
traffic. It also provides standard interfaces for them to monitor
the security functions hosted and managed by service providers.
[I2NSF-Problem] describes the motivation and the problem space for
Interface to Network Security Functions.
xxx, et al. Expires September 16, 2016 [Page 3]
Internet-Draft I2NSF Framework March 2016
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.
BSS: Business Support System
Controller: used interchangeably with Service Provider Security
Controller or management system throughout this
document.
FW: Firewall
IDS: Intrusion Detection System
IPS: Intrusion Protection System
NSF: Network Security Functions, defined by [I2NSF-Problem]
OSS: Operation Support System
vNSF: refers to NSF being instantiated on Virtual Machines.
3. Interfaces to Flow-based NSFs
The emergence of SDN and NFV have resulted in the need to create
application programming interfaces (APIs) in support of dynamic
requests from various applications or application controllers.
Flow-based NSFs [I2NSF-Problem] inspects packets in the order that
they are received. The Interface to Flow-based NSFs can be generally
grouped into three types:
xxx, et al. Expires September 16, 2016 [Page 4]
Internet-Draft I2NSF Framework March 2016
1) Configuration - deals with the management and configuration of
the NSF device itself, such as port address configurations.
Configuration deals with attributes that are relatively
static.
2) Signaling - which represents logging and query functions
between the NSF and external systems. Signaling API functions
may also be defined by other protocols, such as SYSLOG and
DOTS.
3) Rules Provisioning - used to control the rules that govern how
packets are treated by the NSFs. Due to the need of
applications/controllers to dynamically control what traffic
they need to receive, much of the I2NSF efforts towards
interface development will be in this area.
This draft proposes that a rule provisioning interface to NSFs can
be developed on a packet- or flow-based paradigm. A common trait of
NSFs is in the processing of packets based on the content
(header/payload) and/or context (session state, authentication
state, etc) of the received packets.
An important concept underlying this framework is the fact that
attackers do not have standards as to how to attack networks, so it
is equally important not to constrain NSF developers to offering a
limited set of security functions. In other words, the introduction
of I2NSF standards should not make it easier for attackers to
compromise the network. Therefore, in constructing standards for
rules provisioning interfaces to NSFs, it is equally important to
allow support for vendor-specific functions, as this enables the
introduction of NSFs that evolve to meet new threats. Proposed
standards for rules provisioning interfaces to NSFs SHOULD NOT:
- Narrowly define NSF categories, or their roles when implemented
within a network
- Attempt to impose functional requirements or constraints,
either directly or indirectly, upon NSF developers
xxx, et al. Expires September 16, 2016 [Page 5]
Internet-Draft I2NSF Framework March 2016
- Be a limited lowest common denominator approach, where
interfaces can only support a limited set of standardized
functions, without allowing for vendor-specific functions
- Be seen as endorsing a best common practice for the
implementation of NSFs
By using a packet/flow-based approach to the design of such
provisioning interfaces, the goal is to create a workable interface
to NSFs that aids in their integration within legacy, SDN, and/or
NFV environments, while avoiding potential constraints which could
limit their functional capabilities.
Even though security functions come in a variety of form factors and
have different features, provisioning to flow-based NSFs can be
standardized by using Event - Condition - Action (ECA) policy
rulesets.
An Event, when used in the context of policy rules for a flow-based
NSF, is used to determine whether the condition clause of the Policy
Rule can be evaluated or not. Here are some examples of I2NSF
Events:
- defining a clause, of the canonical form {variable, operator,
value}, to represent an Event (e.g., time == 08:00)
- using an Event object as the variable or the value in the above
clause (e.g., use one or more attributes from one or more Event
objects in the comparison clause)
- using a Collection object to collect Events for aggregation,
filtering, and/or correlation operations as part of the Event
clause processing
- encoding the entire Event expression into an attribute
A Condition, when used in the context of policy rules for flow-based
NSFs, is used to determine whether or not the set of Actions in that
Policy Rule can be executed or not. A condition can be based on
various combinations of the content (header/payload) and/or the
context (session state, authentication state, etc) of the received
packets:
xxx, et al. Expires September 16, 2016 [Page 6]
Internet-Draft I2NSF Framework March 2016
- Packet content values are based on one or more packet headers,
data from the packet payload, bits in the packet, or something
derived from the packet;
- Context values are based on measured and inferred knowledge
that define the state and environment in which a managed entity
exists or has existed. In addition to state data, this includes
data from sessions, direction of the traffic, time, and geo-
location information. State refers to the behavior of a managed
entity at a particular point in time. Hence, it may refer to
situations in which multiple pieces of information that are not
available at the same time must be analyzed. For example,
tracking established TCP connections (connections that have gone
through the initial three-way handshake).
Actions for flow-based NSFs include:
- Action ingress processing, such as pass, drop, mirroring, etc;
- Action egress processing, such as invoke signaling, tunnel
encapsulation, packet forwarding and/or transformation;
- Applying a specific Functional Profile or signature - e.g., an
IPS Profile, a signature file, an anti-virus file, or a URL
filtering file. Many flow-based NSFs utilize profile and/or
signature files to achieve more effective threat detection and
prevention. It is not uncommon for a NSF to apply different
profiles and/or signatures for different flows. Some
profiles/signatures do not require any knowledge of past or
future activities, while others are stateful, and may need to
maintain state for a specific length of time.
The functional profile or signature file is one of the key
properties that determine the effectiveness of the NSF, and is
mostly vendor-specific today. The rulesets and software interfaces
of I2NSF aim to standardize the form and function of profile and
signature files while supporting vendor-specific functions of each.
4. Reference Models in Managing Flow-based NSFs
This document only focuses on the framework of rules provisioning
for and monitoring of flow-based NSFs.
xxx, et al. Expires September 16, 2016 [Page 7]
Internet-Draft I2NSF Framework March 2016
The following figure shows various interfaces for managing the
provisioning & monitoring aspects of flow-based NSFs.
+-------------------------------------+
| Client or App Controller |
| (e.g., Video Conference Ctrl Admin, |
| OSS/BSS, or Service Orchestration |
+----------+--------------------------+
|
| Client Facing (Service Layer) Interface
|
+-----+---------------+
|Network Operator mgmt| +-------------+
| Security Controller | < --------- > | Vendor |
+---------------+-----+ Vendor Facing | System |
| Interface +-------------+
|
| NSF Facing (capability) Interface
|
+---------------------------+-----------------------+
| |
| |
+---+--+ +------+ +------+ +--+---+
+ NSF-1+ ------- + NSF-n+ +NSF-1 + ----- +NSF-m + . . .
+------+ +------+ +------+ +------+
Vendor A Vendor B
Figure 1: Multiple Interfaces
4.1. NSF Facing (Capability Layer) Interface
This is the interface between the Service Provider's management
system (or Security Controller) and the set of NSFs that are
selected to enforce the desired network security. This interface
defines the features available for each NSF that the management
system can choose to invoke for a particular packet or flow. Note
that the management system does not need to use all features for a
given NSF, nor does it need to use all available NSFs. Hence, this
abstraction enables the same relative features from diverse NSFs
from different vendors to be selected.
xxx, et al. Expires September 16, 2016 [Page 8]
Internet-Draft I2NSF Framework March 2016
This interface is called the Capability Interface in the I2NSF
context.
4.2. Client Facing (Service Layer) Interface
This interface is for clients or Application Controller to express
and monitor security policies for their specific flows. The Client
Facing interface is called the Service Layer Interface in the
I2NSF context. The I2NSF Service Layer allows the client to define
and monitor the client specific policies and their execution
status.
A single client layer policy may need multiple NSFs (or multiple
instantiations of the same NSF) to achieve the desired
enforcement.
4.3. Vendor Facing Interface
NSFs provided by different vendors have different capabilities. In
order to automate the process of utilizing multiple types of
security functions provided by different vendors, it is necessary
to have an interface for vendors to register their NSFs indicating
the capabilities of their NSFs.
The Registration Interface can be defined statically or
instantiated dynamically at runtime. If a new functionality that
is exposed to the user is added to an NSF, the vendor MUST notify
the network operator's management system or security controller of
its updated functionality via the Registration Interface.
4.4. The Network Connecting the Security Controller and NSFs
Most likely the NSFs are not directly attached to the Security
Controller; for example, NSFs can be distributed across the
network. The network that connects the Security Controller with
the NSFs can be the same network that carries the data traffic, or
can be a dedicated network for management purposes only. In either
case, packet loss could happen due to failure, congestion, or
other reasons.
xxx, et al. Expires September 16, 2016 [Page 9]
Internet-Draft I2NSF Framework March 2016
Therefore, the transport mechanism used to carry the control
messages and monitoring information should provide reliable
message delivery. Transport redundancy mechanisms such as
Multipath TCP (MPTCP) [MPTCP] and the Stream Control Transmission
Protocol (SCTP) [RFC3286] will need to be evaluated for
applicability. Latency requirements for control message delivery
must also be evaluated.
The network connection between the Security Controller and NSFs
could be:
- Closed environments, where there is only one administrative
domain. Less restrictive access control and simpler validation
can be used inside the domain because of the protected
environment.
- Open environments, where some NSFs (virtual or physical) can be
hosted in external administrative domains or reached via secure
external network domains. This requires more restrictive
security control to be placed over the I2NSF interface. Not
only must the information over the I2NSF interfaces use trusted
channels, such as TLS, SASL (RFC4422), or the combination of the
two, but also require proper authentication as described in
[Remote-Attestation].
Over the Open Environment, I2NSF needs to provide identity
information, along with additional data that Authentication,
Authorization, and Accounting (AAA) frameworks can use. This
enables those frameworks to perform AAA functions on the I2NSF
traffic.
4.5. Interface to vNSFs
Even though there is no difference between virtual network
security functions (vNSF) and physical NSFs from the policy
provisioning perspective, there are some unique characteristics in
interfacing to the vNSFs:
- There could be multiple instantiations of one single NSF that
has been distributed across a network. When different
instantiations are visible to the Security Controller, different
xxx, et al. Expires September 16, 2016 [Page 10]
Internet-Draft I2NSF Framework March 2016
policies may be applied to different instantiations of an
individual NSF (e.g., to reflect the different roles that each
vNSF is designated for).
- When multiple instantiations of one single NSF appear as one
single entity to the Security Controller, the policy
provisioning has to be sent to the NSF's sub-controller, which
in turn disseminates the polices to the corresponding
instantiations of the NSF, as shown in the Figure 2 below.
- Policies to one vNSF may need to be retrieved and moved to
another vNSF of the same type when client flows are moved from
one vNSF to another.
- Multiple vNSFs may share the same physical platform
- There may be scenarios where multiple vNSFs collectively perform
the security policies needed.
+------------------------+
| Security Controller |
+------------------------+
^ ^
| |
+-----------+ +------------+
| |
v v
+ - - - - - - - - - - - - - - - + + - - - - - - - - - - - - - - - +
| NSF-A +--------------+ | | NSF-B +--------------+ |
| |Sub Controller| | | |sub Controller| |
| +--------------+ | | +--------------+ |
| + - - - - - - - - - - - - - + | | + - - - - - - - - - - - - - + |
| |+---------+ +---------+| | | |+---------+ +---------+| |
| || NSF-A#1 | ... | NSF-A#n|| | | || NSF-B#1| ... | NSF-B#m|| |
| |+---------+ +---------+| | | |+---------+ +---------+| |
| | NSF-A cluster | | | | NSF-B cluster | |
| + - - - - - - - - - - - - - + | | + - - - - - - - - - - - - - + |
+ - - - - - - - - - - - - - - - + + - - - - - - - - - - - - - - - +
Figure 2: Cluster of NSF Instantiations Management
5. Flow-based NSF Capability Characterization
There are many types of flow-based NSFs. Firewall, IPS, and IDS are
the commonly deployed flow-based NSFs. However, the differences
xxx, et al. Expires September 16, 2016 [Page 11]
Internet-Draft I2NSF Framework March 2016
among them are definitely blurring, due to technological capacity
increases, integration of platforms, and new threats. At their core:
. Firewall - A device or a function that analyzes packet headers and
enforces policy based on protocol type, source address,
destination address, source port, destination port, and/or other
attributes of the packet header. Packets that do not match policy
are rejected. Note that additional functions, such as logging and
notification of a system administrator, could optionally be
enforced as well.
. IDS (Intrusion Detection System) - A device or function that
analyzes packets, both header and payload, looking for known
events. When a known event is detected, a log message is generated
detailing the event. Note that additional functions, such as
notification of a system administrator, could optionally be
enforced as well.
. IPS (Intrusion Prevention System) - A device or function that
analyzes packets, both header and payload, looking for known
events. When a known event is detected, the packet is rejected.
Note that additional functions, such as logging and notification
of a system administrator, could optionally be enforced as well.
To prevent constraints on NSF vendors' creativity and innovation,
this document recommends the Flow-based NSF interfaces to be
designed from the paradigm of processing packets in the network.
Flow-based NSFs ultimately are packet-processing engines that
inspect packets traversing networks, either directly or in the
context of sessions in which the packet is associated.
Flow-based NSFs differ in the depth of packet header or payload they
can inspect, the various session/context states they can maintain,
and the specific profiles and the actions they can apply. An example
of a session is "allowing outbound connection requests and only
allowing return traffic from the external network".
Accordingly, the NSF capabilities are characterized by the level of
packet processing and context that a NSF supports, the profiles and
the actions that the NSF can apply. The term "context" includes
anything that can influence the action(s) taken by the NSF, such as
time of day, location, session state, and events.
xxx, et al. Expires September 16, 2016 [Page 12]
Internet-Draft I2NSF Framework March 2016
Vendors can register their NSFs using Packet Content Match
categories. The IDR Flow Specification [RFC5575] has specified 12
different packet header matching types. More packet content matching
types have been proposed in the IDR WG. I2NSF should re-use the
packet matching types being specified as much as possible. More
matching types might be added for Flow-based NSFS. Tables 1-4 below
list the applicable packet content categories that can be
potentially used as packet matching types by Flow-based NSFs:
+-----------------------------------------------------------+
| Packet Content Matching Capability Index |
+---------------+-------------------------------------------+
| Layer 2 | Layer 2 header fields: |
| Header | Source/Destination/s-VID/c-VID/EtherType/.|
| | |
|---------------+-------------------------------------------+
| Layer 3 | Layer header fields: |
| | protocol |
| IPv4 Header | dest port |
| | src port |
| | src address |
| | dest address |
| | dscp |
| | length |
| | flags |
| | ttl |
| | |
| IPv6 Header | |
| | addr |
| | protocol/nh |
| | src port |
| | dest port |
| | src address |
| | dest address |
| | length |
| | traffic class |
| | hop limit |
| | flow label |
| | dscp |
| | |
| TCP | Port |
| SCTP | syn |
| DCCP | ack |
| | fin |
| | rst |
| | ? psh |
xxx, et al. Expires September 16, 2016 [Page 13]
Internet-Draft I2NSF Framework March 2016
| | ? urg |
| | ? window |
| | sockstress |
| | Note: bitmap could be used to |
| | represent all the fields |
| | |
| UDP | |
| | flood abuse |
| | fragment abuse |
| | Port |
| HTTP layer | |
| | | hash collision |
| | | http - get flood |
| | | http - post flood |
| | | http - random/invalid url |
| | | http - slowloris |
| | | http - slow read |
| | | http - r-u-dead-yet (rudy) |
| | | http - malformed request |
| | | http - xss |
| | | https - ssl session exhaustion |
+---------------+----------+--------------------------------+
| IETF PCP | Configurable |
| | Ports |
| | |
+---------------+-------------------------------------------+
| IETF TRAM | profile |
| | |
| | |
|---------------+-------------------------------------------+
Table 1: Subject Capability Index
+-----------------------------------------------------------+
| context matching Capability Index |
+---------------+-------------------------------------------+
| Session | Session state, |
| | bidirectional state |
| | |
+---------------+-------------------------------------------+
| Time | time span |
| | time occurrence |
+---------------+-------------------------------------------+
| Events | Event URL, variables |
+---------------+-------------------------------------------+
| Location | Text string, GPS coords, URL |
+---------------+-------------------------------------------+
| Connection | Internet (unsecured), Internet |
| Type | (secured by VPN, etc.), Intranet, ... |
xxx, et al. Expires September 16, 2016 [Page 14]
Internet-Draft I2NSF Framework March 2016
+---------------+-------------------------------------------+
| Direction | Inbound, Outbound |
+---------------+-------------------------------------------+
| State | Authentication State |
| | Authorization State |
| | Accounting State |
| | Session State |
+---------------+-------------------------------------------+
Table 2: Object Capability Index
+-----------------------------------------------------------+
| Action Capability Index |
+---------------+-------------------------------------------+
| Ingress port | SFC header termination, |
| | VxLAN header termination |
+---------------+-------------------------------------------+
| | Pass |
| Actions | Deny |
| | Mirror |
| | Simple Statistics: Count (X min; Day;..)|
| | Client specified Functions: URL |
+---------------+-------------------------------------------+
| Egress | Encap SFC, VxLAN, or other header |
+---------------+-------------------------------------------+
Table 3: Action Capability Index
+-----------------------------------------------------------+
| Functional profile Index |
+---------------+-------------------------------------------+
| Profile types | Name, type, or |
| Signature | Flexible Profile/signature URL |
| | Command for Controller to enable/disable |
| | |
+---------------+-------------------------------------------+
Table 4: Function Capability Index
6. Structure of Rules for governing NSFs
6.1. Capability Layer Rules and Monitoring
The purpose of the Capability Layer is to define explicit rules for
individual NSFs to treat packets, as well as methods to monitor the
execution status of those functions.
xxx, et al. Expires September 16, 2016 [Page 15]
Internet-Draft I2NSF Framework March 2016
[ACL-MODEL] has defined rules for the Access Control List supported
by most routers/switches that forward packets based on packets' L2,
L3, or sometimes L4 headers. The actions for Access Control Lists
include Pass, Drop, or Redirect.
The functional profiles (or signatures) for NSFs are not present in
[ACL-MODEL] because the functional profiles are unique to specific
NSFs. For example, most vendors' IPS/IDS have their proprietary
functions/profiles. One of the goals of I2NSF is to define a common
envelop format for exchanging or sharing profiles among different
organizations to achieve more effective protection against threats.
The "packet content matching" of the I2NSF policies should not only
include the matching criteria specified by [ACL-MODEL] but also the
L4-L7 fields depending on the NSFs selected.
Some Flow-based NSFs need matching criteria that include the context
associated with the packets.
The I2NSF "actions" should extend the actions specified by [ACL-
MODEL] to include applying statistics functions, threat profiles, or
signature files that clients provide.
Policy consistency among multiple security function instances is
very critical because security policies are no longer maintained by
one central security device, but instead are enforced by multiple
security functions instantiated at various locations.
6.2. Service Layer Policy
This layer is for clients or an Application Controller to express
and monitor the needed security policies for their specific flows.
Some Customers may not have security skills. As such, they are not
able to express requirements or security policies that are precise
enough. These customers may instead express expectations or intent
of the functionality desired by their security policies. Customers
may also express guidelines such as which certain types of
destinations are not allowed for certain groups. As a result, there
could be different depths or layers of Service Layer policies. Here
are some examples of more abstract service layer security Policies:
o Pass for Subscriber "xxx"
o enable basic parental control
xxx, et al. Expires September 16, 2016 [Page 16]
Internet-Draft I2NSF Framework March 2016
o enable "school protection control"
o allow Internet traffic from 8:30 to 20:00
o scan email for malware detection protect traffic to
corporate network with integrity and confidentiality
o remove tracking data from Facebook [website =
*.facebook.com]
o my son is allowed to access facebook from 18:30 to 20:00
One Service Layer Security Policy may need multiple security
functions at various locations to achieve the enforcement. Service
layer Security Policy may need to be updated by clients or
Application controllers when clients' service requirements have been
changed. Some service layer policies may not be granted because the
carrier or Enterprises imposes additional constraints on what a
client can have. [I2NSF-Demo] describes an implementation of
translating a set of service layer policies to the Capability Layer
instructions to NSFs.
I2NSF will first focus on simple service layer policies that are
modeled as closely as possible on the Capability Layer. The I2NSF
simple service layer should have similar structure as the I2NSF
capability layer, but with more of a client-oriented expression for
the packet content, context, and other parts of an ECA policy rule.
This enables the client to construct an ECA policy rule without
having to know its detailed structure or syntax.
There have been several industry initiatives to address network
policies, such as OpenStack's Group-based Policy (GBP), IETF Policy
Core Information Model-PCIM [RFC3060, RFC3460], and others. I2NSF
will not work on general network service policies, but instead will
define a standard interface for clients/applications to inform the
Flow-based NSFs on the rules for treating traffic.
However, the notion of Groups (or roles), Target, Event, Context (or
Conditions), and Action do cover what is needed for
clients/applications to express the rules on how their flows can be
treated by the Flow-Based NSFs in networks. The goal is to have a
policy structure that can be mapped to the Capability layer's Event-
Condition-Action paradigm.
The I2NSF simple service layer can have the following entities:
- I2NSF-Groups: This is a collection of users, applications,
virtual networks, or traffic patterns to which a service
xxx, et al. Expires September 16, 2016 [Page 17]
Internet-Draft I2NSF Framework March 2016
layer policy can be applied. An I2NSF-Group may be mapped to
a client virtual Subnet (i.e. with private address prefix), a
subnet with public address families, specific applications,
destinations, or any combination of them with logical
operators (Logical AND, OR, or NOT). An I2NSF-Group can have
one or more Policy Rules applied to it.
- Target. This is used by the application client to identify
the set of objects to be affected by the policy rules. A
Target can be mapped to a physical/logical ingress port, a
set of destinations, or a physical/logical egress port.
- Policy Rule. A Policy Rule consists of a set of Policy
Events, Policy Conditions, and Policy Actions. Policy Rules
are triggered by matching Events. If the Event portion of the
Policy Rule evaluates to true, then the Condition portion is
evaluated (otherwise, the Policy Rule terminates and no
action is taken). If the Condition portion of the Policy Rule
evaluates to true, then the set of Actions MAY be executed
and applied to the traffic (otherwise, the Policy Rule
terminates and no action is taken).
- Policy Event. This triggers a determination of whether the
condition portion of a Policy Rule should be evaluated or
not.
- Policy Condition. This determines when the Policy Actions
contained in a Policy Rule are to be applied. It can be
expressed as a direction, a list of L4 ports, time range, or
a protocol, etc.
- Policy Action: This is the action applied to the traffic that
matches the Conditions (and was triggered by the Events). An
action may be a simple ACL action (i.e. allow, deny,
mirroring), applying a well known statistics functions (e.g.
X minutes count, Y hours court), applying client specified
functions (with URL provided), or may refer to an ordered
sequence of functions.
xxx, et al. Expires September 16, 2016 [Page 18]
Internet-Draft I2NSF Framework March 2016
7. Capability Negotiation
When an NSF can't perform the desired provisioning (e.g., due to
resource constraints), it MUST inform the controller.
The protocol needed for this security function/capability
negotiation may be somewhat correlated to the dynamic service
parameter negotiation procedure [RFC7297]. The Connectivity
Provisioning Profile (CPP) template documented in RFC7297, even
though currently covering only Connectivity requirements (but
includes security clauses such as isolation requirements, non-via
nodes, etc.), could be extended as a basis for the negotiation
procedure. Likewise, the companion Connectivity Provisioning
Negotiation Protocol (CPNP) could be a candidate to proceed with
the negotiation procedure.
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.
8. Types of I2NSF clients
It is envisioned that I2NSF clients include:
- Application Controller:
- For example, Video Conference Mgr/Controller needs to
dynamically inform network to allow or deny flows (some of
which are encrypted) based on specific fields in the packets
for a certain time span. Otherwise, some flows can't go
through the NSFs (e.g. FW/IPS/IDS) in the network because the
payload is encrypted or packets' protocol codes are not
recognized by those NSFs.
- Security Administrators
- Enterprise users and applications
xxx, et al. Expires September 16, 2016 [Page 19]
Internet-Draft I2NSF Framework March 2016
- Operator Management System dynamically updates, monitors
and verifies the security policies to NSFs (by different
vendors) in a network.
- Third party system
- Security functions send requests for more sophisticated functions
upon detecting something suspicious, usually via a security
controller.
9. Manageability Considerations
Management of NSFs usually includes:
- life cycle management and resource management of NSFs
- configuration of devices, such as address configuration,
device internal attributes configuration, etc,
- signaling, and
- policy rules provisioning.
I2NSF will only focus on the policy rule provisioning part, i.e.,
the last bullet listed above.
10. Security Considerations
Having a secure access to control and monitor NSFs is crucial for
hosted security service. 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).
11. IANA Considerations
This document requires no IANA actions. RFC Editor: Please remove
this section before publication.
xxx, et al. Expires September 16, 2016 [Page 20]
Internet-Draft I2NSF Framework March 2016
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.
[RFC3060] Moore, B, et al, "Policy Core Information Model (PCIM)",
RFC 3060, Feb 2001.
[RFC3460] Moore, B. "Policy Core Information Model (PCIM)
Extensions", RFC3460, Jan 2003.
[RFC5575] Marques, P, et al, "Dissemination of Flow Specification
Rules", RFC 5575, Aug 2009.
[RFC7297] Boucadair, M., "IP Connectivity Provisioning Profile",
RFC7297, April 2014.
12.2. Informative References
[I2NSF-ACCESS] A. Pastor, et al, "Access Use Cases for an Open OAM
Interface to Virtualized Security Services", <draft-
pastor-i2nsf-access-usecases-00>, Oct 2014.
[I2NSF-DC] M. Zarny, et al, "I2NSF Data Center Use Cases", <draft-
zarny-i2nsf-data-center-use-cases-00>, Oct 2014.
[I2NSF-MOBILE] M. Qi, et al, "Integrated Security with Access
Network Use Case", <draft-qi-i2nsf-access-network-usecase-
00>, Oct 2014
[I2NSF-Problem] L. Dunbar, et al "Interface to Network Security
Functions Problem Statement", <draft-dunbar-i2nsf-problem-
statement-01>, Jan 2015
[ACL-MODEL] D. Bogdanovic, et al, "Network Access Control List (ACL)
YANG Data Model", <draft-ietf-net-acl-model-00>, Nov 2014.
xxx, et al. Expires September 16, 2016 [Page 21]
Internet-Draft I2NSF Framework March 2016
[gs_NFV] ETSI NFV Group Specification, Network Functions
Virtualizsation (NFV) Use Cases. ETSI GS NFV 001v1.1.1,
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.
[I2NSF-Demo] Y. Xie, et al, "Interface to Network Security Functions
Demo Outline Design", <draft-xie-i2nsf-demo-outline-
design-00>, April 2015.
[ITU-T-X1036] ITU-T Recommendation X.1036, "Framework for creation,
storage, distribution and enforcement of policies for
network security", Nov 2007.
13. Acknowledgments
Acknowledgements to xxx for his review and contributions.
This document was prepared using 2-Word-v2.0.template.dot.
xxx, et al. Expires September 16, 2016 [Page 22]
Internet-Draft I2NSF Framework March 2016
Authors' Addresses
Edward Lopez
Fortinet
899 Kifer Road
Sunnyvale, CA 94086
Phone: +1 703 220 0988
Email: elopez@fortinet.com
Diego Lopez
Telefonica
Email: diego.r.lopez@telefonica.com
XiaoJun Zhuang
China Mobile
Email: zhuangxiaojun@chinamobile.com
Linda Dunbar
Huawei
Email: Linda.Dunbar@huawei.com
John Strassner
Huawei
John.sc.Strassner@huawei.com
Joe Parrott
BT
Email: joe.parrott@bt.com
Ramki Krishnan
Dell
Email: ramki_krishnan@dell.com
Seetharama Rao Durbha
CableLabs
Email: S.Durbha@cablelabs.com
xxx, et al. Expires September 16, 2016 [Page 23]
