One document matched: draft-ietf-forces-requirements-09.txt
Differences from draft-ietf-forces-requirements-08.txt
Internet Draft H. Khosravi,
Expiration: November 2003 T. Anderson (Editors)
File: draft-ietf-forces-requirements-09.txt Intel
Working Group: ForCES May 2003
Requirements for Separation of IP Control and Forwarding
draft-ietf-forces-requirements-09.txt
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. 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.
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].
1. Abstract
This document introduces the ForCES architecture and defines a set
of associated terminology. This document also defines a set of
architectural, modeling, and protocol requirements to logically
separate the control and data forwarding planes of an IP (IPv4,
IPv6, etc.) networking device.
Khosravi, et. al. Expires November 2003 [Page 1]
Internet Draft ForCES Requirements May 2003
1. Abstract........................................................1
2. Introduction....................................................2
3. Definitions.....................................................3
4. Architecture....................................................5
5. Architectural Requirements......................................6
6. FE Model Requirements...........................................8
6.1. Types of Logical Functions......................................8
6.2. Variations of Logical Functions.................................8
6.3. Ordering of Logical Functions...................................8
6.4. Flexibility.....................................................9
6.5. Minimal Set of Logical Functions................................9
7. ForCES Protocol Requirements...................................10
8. References.....................................................14
8.1. Normative References...........................................14
8.2. Informative References.........................................14
9. Security Considerations........................................15
10. Authors' Addresses & Acknowledgments..........................15
11. Editors' Contact Information..................................16
2. Introduction
An IP network element is composed of numerous logically separate
entities that cooperate to provide a given functionality (such as a
routing or IP switching) and yet appear as a normal integrated
network element to external entities. Two primary types of network
element components exist: control-plane components and forwarding-
plane components. In general, forwarding-plane components are ASIC,
network-processor, or general-purpose processor-based devices that
handle all data path operations. Conversely, control-plane
components are typically based on general-purpose processors that
provide control functionality such as the processing of routing or
signaling protocols. A standard set of mechanisms for connecting
these components provides increased scalability and allows the
control and forwarding planes to evolve independently, thus
promoting faster innovation.
For the purpose of illustration, let us consider the architecture of
a router to illustrate the concept of separate control and
forwarding planes. The architecture of a router is composed of two
main parts. These components, while inter-related, perform
functions that are largely independent of each other. At the bottom
is the forwarding path that operates in the data-forwarding plane
and is responsible for per-packet processing and forwarding. Above
the forwarding plane is the network operating system that is
responsible for operations in the control plane. In the case of a
router or switch, the network operating system runs routing,
signaling and control protocols (e.g., RIP, OSPF and RSVP) and
dictates the forwarding behavior by manipulating forwarding tables,
Khosravi, et. al. Expires November 2003 [Page 2]
Internet Draft ForCES Requirements May 2003
per-flow QoS tables and access control lists. Typically, the
architecture of these devices combines all of this functionality
into a single functional whole with respect to external entities.
3. Definitions
Addressable Entity (AE) - A physical device that is directly
addressable given some interconnect technology. For example, on IP
networks, it is a device to which we can communicate using an IP
address; and on a switch fabric, it is a device to which we can
communicate using a switch fabric port number.
Physical Forwarding Element (PFE) - An AE that includes hardware
used to provide per-packet processing and handling. This hardware
may consist of (but is not limited to) network processors, ASIC's,
line cards with multiple chips or stand alone box with general-
purpose processors.
Physical Control Element (PCE) - An AE that includes hardware used
to provide control functionality. This hardware typically includes
a general-purpose processor.
Forwarding Element (FE) - A logical entity that implements the
ForCES protocol. FEs use the underlying hardware to provide per-
packet processing and handling as directed/controlled by a CE via
the ForCES protocol. FEs may happen to be a single blade(or PFE), a
partition of a PFE or multiple PFEs.
Control Element (CE) - A logical entity that implements the ForCES
protocol and uses it to instruct one or more FEs how to process
packets. CEs handle functionality such as the execution of control
and signaling protocols. CEs may consist of PCE partitions or whole
PCEs.
Pre-association Phase - The period of time during which a FE Manager
(see below) and a CE Manager (see below) are determining which FE
and CE should be part of the same network element. Any partitioning
of PFEs and PCEs occurs during this phase.
Post-association Phase - The period of time during which a FE does
know which CE is to control it and vice versa, including the time
during which the CE and FE are establishing communication with one
another.
ForCES Protocol - While there may be multiple protocols used within
the overall ForCES architecture, the term "ForCES protocol" refers
only to the ForCES post-association phase protocol (see below).
Khosravi, et. al. Expires November 2003 [Page 3]
Internet Draft ForCES Requirements May 2003
ForCES Post-Association Phase Protocol - The protocol used for post-
association phase communication between CEs and FEs. This protocol
does not apply to CE-to-CE communication, FE-to-FE communication, or
to communication between FE and CE managers. The ForCES protocol is
a master-slave protocol in which FEs are slaves and CEs are masters.
This protocol includes both the management of the communication
channel (e.g., connection establishment, heartbeats) and the control
messages themselves. This protocol could be a single protocol or
could consist of multiple protocols working together.
FE Model - A model that describes the logical processing functions
of a FE.
FE Manager - A logical entity that operates in the pre-association
phase and is responsible for determining to which CE(s) a FE should
communicate. This process is called CE discovery and may involve
the FE manager learning the capabilities of available CEs. A FE
manager may use anything from a static configuration to a pre-
association phase protocol (see below) to determine which CE(s) to
use, however this is currently out of scope. Being a logical
entity, a FE manager might be physically combined with any of the
other logical entities mentioned in this section.
CE Manager - A logical entity that operates in the pre-association
phase and is responsible for determining to which FE(s) a CE should
communicate. This process is called FE discovery and may involve
the CE manager learning the capabilities of available FEs. A CE
manager may use anything from a static configuration to a pre-
association phase protocol (see below) to determine which FE to use,
however this is currently out of scope. Being a logical entity, a
CE manager might be physically combined with any of the other
logical entities mentioned in this section.
Pre-association Phase Protocol - A protocol between FE managers and
CE managers that is used to determine which CEs or FEs to use. A
pre-association phase protocol may include a CE and/or FE capability
discovery mechanism. Note that this capability discovery process is
wholly separate from (and does not replace) that used within the
ForCES protocol (see Section 7, requirement #1). However, the two
capability discovery mechanisms may utilize the same FE model (see
Section 6). Pre-association phase protocols are not discussed
further in this document.
ForCES Network Element (NE) - An entity composed of one or more CEs
and one or more FEs. To entities outside a NE, the NE represents a
single point of management. Similarly, a NE usually hides its
internal organization from external entities.
ForCES Protocol Element - A FE or CE.
Khosravi, et. al. Expires November 2003 [Page 4]
Internet Draft ForCES Requirements May 2003
High Touch Capability - This term will be used to apply to the
capabilities found in some forwarders to take action on the contents
or headers of a packet based on content other than what is found in
the IP header. Examples of these capabilities include NAT-PT,
firewall, and L7 content recognition.
4. Architecture
The chief components of a NE architecture are the CE, the FE, and
the interconnect protocol. The CE is responsible for operations
such as signaling and control protocol processing and the
implementation of management protocols. Based on the information
acquired through control processing, the CE(s) dictates the packet-
forwarding behavior of the FE(s) via the interconnect protocol. For
example, the CE might control a FE by manipulating its forwarding
tables, the state of its interfaces, or by adding or removing a NAT
binding.
The FE operates in the forwarding plane and is responsible for per-
packet processing and handling. By allowing the control and
forwarding planes to evolve independently, different types of FEs
can be developed - some general purpose and others more specialized.
Some functions that FEs could perform include layer 3 forwarding,
metering, shaping, firewall, NAT, encapsulation (e.g., tunneling),
decapsulation, encryption, accounting, etc. Nearly all combinations
of these functions may be present in practical FEs.
Below is a diagram illustrating an example NE composed of a CE and
two FEs. Both FEs and CE require minimal configuration as part of
the pre-configuration process and this may be done by FE Manager and
CE Manager respectively. Apart from this, there is no defined role
for FE Manager and CE Manager. These components are out of scope of
the architecture and requirements for the ForCES protocol, which
only involves CEs and FEs.
--------------------------------
| NE |
| ------------- |
| | CE | |
| ------------- |
| / \ |
| / \ |
| / \ |
| / \ |
| ----------- ----------- |
| | FE | | FE | |
| ----------- ----------- |
| | | | | | | | | |
Khosravi, et. al. Expires November 2003 [Page 5]
Internet Draft ForCES Requirements May 2003
| | | | | | | | | |
| | | | | | | | | |
| | | | | | | | | |
--------------------------------
| | | | | | | |
| | | | | | | |
5. Architectural Requirements
The following are the architectural requirements:
1) CEs and FEs MUST be able to connect by a variety of interconnect
technologies. Examples of interconnect technologies used in current
architectures include Ethernet,bus backplanes, and ATM (cell)
fabrics. FEs MAY be connected to each other via a different
technology than that used for CE/FE communication.
2) FEs MUST support a minimal set of capabilities necessary for
establishing network connectivity (e.g., interface discovery, port
up/down functions). Beyond this minimal set, the ForCES
architecture MUST NOT restrict the types or numbers of capabilities
that FEs may contain.
3) Packets MUST be able to arrive at the NE by one FE and leave the
NE via a different FE.
4) A NE MUST support the appearance of a single functional device.
For example, in a router, the TTL of the packet should be
decremented only once as it traverses the NE regardless of how many
FEs through which it passes. However, external entities (e.g., FE
managers and CE managers) MAY have direct access to individual
ForCES protocol elements for providing information to transition
them from the pre-association to post-association phase.
5) The architecture MUST provide a way to prevent unauthorized
ForCES protocol elements from joining a NE.(For more protocol
details, refer to section 7 requirement# 2)
6) A FE MUST be able to asynchronously inform the CE of a failure or
increase/decrease in available resources or capabilities on the FE.
Thus the FE MUST support error monitoring and reporting. (Since
there is not a strict 1-to-1 mapping between FEs and PFEs, it is
possible for the relationship between a FE and its physical
resources to change over time). For example, the number of physical
ports or the amount of memory allocated to a FE may vary over time.
The CE needs to be informed of such changes so that it can control
the FE in an accurate way.
Khosravi, et. al. Expires November 2003 [Page 6]
Internet Draft ForCES Requirements May 2003
7) The architecture MUST support mechanisms for CE redundancy or CE
failover. This includes the ability for CEs and FEs to determine
when there is a loss of association between them, ability to restore
association and efficient state (re)synchronization mechanisms. This
also includes the ability to preset the actions an FE will take in
reaction to loss of association to its CE e.g., whether the FE will
continue to forward packets or whether it will halt operations.
8) FEs MUST be able to redirect control packets (such as RIP, OSPF
messages) addressed to their interfaces to the CE. They MUST also
redirect other relevant packets (e.g., such as those with Router
Alert Option set) to their CE. The CEs MUST be able to configure the
packet redirection information/filters on the FEs. The CEs MUST also
be able to create packets and have its FEs deliver them.
9) Any proposed ForCES architectures MUST explain how that
architecture supports all of the router functions as defined in
[RFC1812]. IPv4 Forwarding functions such IP header validation,
performing longest prefix match algorithm, TTL decrement, Checksum
calculation, generation of ICMP error messages, etc defined in RFC
1812 should be explained.
10) In a ForCES NE, the FEs MUST be able to provide their topology
information (topology by which the FEs in the NE are connected) to
the CE(s).
11) The ForCES NE architecture MUST be capable of supporting (i.e.,
must scale to) at least hundreds of FEs and tens of thousands of
ports.
12) The ForCES architecture MUST allow FEs AND CEs to join and leave
NEs dynamically.
13) The ForCES NE architecture MUST support multiple CEs and FEs.
However, coordination between CEs is out of scope of ForCES.
14) For pre-association phase setup, monitoring, configuration
issues, it MAY be useful to use standard management mechanisms for
CEs and FEs. The ForCES architecture and requirements do not
preclude this. In general, for post-association phase, most
management tasks SHOULD be done through interaction with the CE. In
certain conditions (e.g. CE/FE disconnection), it may be useful to
allow management tools (e.g. SNMP) to be used to diagnose and repair
problems. The following guidelines MUST be observed:
1. The ability for a management tool (e.g. SNMP) to be used to read
(but not change) the state of FE SHOULD NOT be precluded.
2. It MUST NOT be possible for management tools (e.g. SNMP, etc) to
change the state of a FE in a manner that affects overall NE
behavior without the CE being notified.
Khosravi, et. al. Expires November 2003 [Page 7]
Internet Draft ForCES Requirements May 2003
6. FE Model Requirements
The variety of FE functionality that the ForCES architecture allows
poses a potential problem for CEs. In order for a CE to effectively
control a FE, the CE must understand how the FE processes packets.
We therefore REQUIRE that a FE model be created that can express the
logical packet processing capabilities of a FE. This model will be
used in the ForCES protocol to describe FE capabilities (see Section
7, requirement #1). The FE model MUST define both a capability model
and a state model, which expresses the current configuration of the
device. The FE model MUST also support multiple FEs in the NE
architecture.
6.1. Types of Logical Functions
The FE model MUST express what logical functions can be applied to
packets as they pass through a FE.
Logical functions are the packet processing functions that are
applied to the packets as they are forwarded through a FE. Examples
of logical functions are layer 3 forwarding, firewall, NAT, shaping.
Section 6.5 defines the minimal set of logical functions that the FE
Model MUST support.
6.2. Variations of Logical Functions
The FE model MUST be capable of supporting/allowing variations in
the way logical functions are implemented on a FE. For example, on a
certain FE the forwarding logical function might have information
about both the next hop IP address and the next hop MAC address,
while on another FE these might be implemented as separate logical
functions. Another example would be NAT functionality that can have
several flavors such as Traditional/Outbound NAT, Bi-directional
NAT, Twice NAT, Multihomed NAT [RFC2663]. The model must be flexible
enough to allow such variations in functions.
6.3. Ordering of Logical Functions
The model MUST be capable of describing the order in which these
logical functions are applied in a FE. The ordering of logical
functions is important in many cases. For example, a NAT function
may change a packet's source or destination IP address. Any number
of other logical functions (e.g., layer 3 forwarding, ingress/egress
firewall, shaping, accounting) may make use of the source or
destination IP address when making decisions. The CE needs to know
whether to configure these logical functions with the pre-NAT or
post-NAT IP address. Furthermore, the model MUST be capable of
expressing multiple instances of the same logical function in a FE's
processing path. Using NAT again as an example, one NAT function is
typically performed before the forwarding decision (packets arriving
externally have their public addresses replaced with private
Khosravi, et. al. Expires November 2003 [Page 8]
Internet Draft ForCES Requirements May 2003
addresses) and one NAT function is performed after the forwarding
decision (for packets exiting the domain, their private addresses
are replaced by public ones).
6.4. Flexibility
Finally, the FE model SHOULD provide a flexible infrastructure in
which new logical functions and new classification, action, and
parameterization data can be easily added. In addition, the FE
model MUST be capable of describing the types of statistics gathered
by each logical function.
6.5. Minimal Set of Logical Functions
The rest of this section defines a minimal set of logical functions
that any FE model MUST support. This minimal set DOES NOT imply
that all FEs must provide this functionality. Instead, these
requirements only specify that the model must be capable of
expressing the capabilities that FEs may choose to provide.
1)Port Functions
The FE model MUST be capable of expressing the number of ports on
the device, the static attributes of each port (e.g., port type,
link speed), and the configurable attributes of each port (e.g., IP
address, administrative status).
2)Forwarding Functions
The FE model MUST be capable of expressing the data that can be used
by the forwarding function to make a forwarding decision. Support
for IPv4 and IPv6 unicast and multicast forwarding functions MUST be
provided by the model.
3)QoS Functions
The FE model MUST allow a FE to express its QoS capabilities in
terms of, e.g., metering, policing, shaping, and queuing functions.
The FE model MUST be capable of expressing the use of these
functions to provide IntServ or DiffServ functionality as described
in [RFC2211], [RFC2212], [RFC2215], [RFC2475], and [RFC3290].
4)Generic Filtering Functions
The FE model MUST be capable of expressing complex sets of filtering
functions. The model MUST be able to express the existence of these
functions at arbitrary points in the sequence of a FE's packet
processing functions. The FE model MUST be capable of expressing a
wide range of classification abilities from single fields (e.g.,
destination address) to arbitrary n-tuples. Similarly, the FE model
MUST be capable of expressing what actions these filtering functions
can perform on packets that the classifier matches.
Khosravi, et. al. Expires November 2003 [Page 9]
Internet Draft ForCES Requirements May 2003
5)Vendor-Specific Functions
The FE model SHOULD be extensible so that new, currently unknown FE
functionality can be expressed. The FE Model SHOULD NOT be extended
to express standard/common functions in a proprietary manner. This
would NOT be ForCES compliant.
6)High-Touch Functions
The FE model MUST be capable of expressing the encapsulation and
tunneling capabilities of a FE. The FE model MUST support functions
that mark the class of service that a packet should receive (i.e.
IPv4 header TOS octet or the IPv6 Traffic Class octet). The FE
model MAY support other high touch functions (e.g., NAT, ALG).
7)Security Functions
The FE model MUST be capable of expressing the types of encryption
that may be applied to packets in the forwarding path.
8)Off-loaded Functions
Per-packet processing can leave state in the FE, so that logical
functions executed during packet processing can perform in a
consistent manner (for instance, each packet may update the state of
the token bucket occupancy of a give policer). In addition, FEs MUST
allow logical functions to execute asynchronously from packet
processing, according to a certain finite-state machine, in order to
perform functions that are, for instance, off-loaded from the CE to
the FE. The FE model MUST be capable of expressing these
asynchronous functions. Examples of such functions include the
finite-state machine execution required by TCP termination or OSPF
Hello processing, triggered not only by packet events, but by timer
events as well. This Does NOT mean off-loading of any piece of code
to an FE, just that the FE Model should be able to express existing
Off-loaded functions on an FE.
9)IPFLOW/PSAMP Functions
Several applications such as, Usage-based Accounting, Traffic
engineering, require flow-based IP traffic measurements from Network
Elements. [IPFLOW] defines architecture for IP traffic flow
monitoring, measuring and exporting. The FE model SHOULD be able to
express metering functions and flow accounting needed for exporting
IP traffic flow information.
Similarly to support measurement-based applications, [PSAMP]
describes a framework to define a standard set of capabilities for
network elements to sample subsets of packets by statistical and
other methods. The FE model SHOULD be able to express statistical
packet filtering functions and packet information needed for
supporting packet sampling applications.
7. ForCES Protocol Requirements
Khosravi, et. al. Expires November 2003 [Page 10]
Internet Draft ForCES Requirements May 2003
This section specifies some of the requirements that the ForCES
protocol MUST meet.
1)Configuration of Modeled Elements
The ForCES protocol MUST allow the CEs to determine the capabilities
of each FE. These capabilities SHALL be expressed using the FE
model whose requirements are defined in Section 6. Furthermore, the
protocol MUST provide a means for the CEs to control all the FE
capabilities that are discovered through the FE model. The protocol
MUST be able to add/remove classification/action entries, set/delete
parameters, query statistics, and register for and receive events.
2)Support for Secure Communication
a) FE configuration will contain information critical to the
functioning of a network (e.g. IP Forwarding Tables). As such, it
MUST be possible to ensure the integrity of all ForCES protocol
messages and protect against man-in-the-middle attacks.
b) FE configuration information may also contain information derived
from business relationships (e.g. service level agreements).
Because of the confidential nature of the information, it MUST be
possible to secure (make private) all ForCES protocol messages.
c) In order to ensure that authorized CEs and FEs are participating
in a NE and defend against CE or FE impersonation attacks, the
ForCES architecture MUST select a means of authentication for CEs
and FEs.
d) In some deployments ForCES is expected to be deployed between CEs
and FEs connected to each other inside a box over a backplane,
where physical security of the box ensures that man-in-the-middle,
snooping, and impersonation attacks are not possible. In such
scenarios the ForCES architecture MAY rely on the physical
security of the box to defend against these attacks and protocol
mechanisms May be turned off.
e) In the case when CEs and FEs are connected over a network,
security mechanisms MUST be specified or selected that protect the
ForCES protocol against such attacks. Any security solution used
for ForCES MUST specify how it deals with such attacks.
3)Scalability
The ForCES protocol MUST be capable of supporting (i.e., must scale
to) at least hundreds of FEs and tens of thousands of ports. For
example, the ForCES protocol field sizes corresponding to FE or port
numbers SHALL be large enough to support the minimum required
numbers. This requirement does not relate to the performance of a
NE as the number of FEs or ports in the NE grows.
4)Multihop
When the CEs and FEs are separated beyond a single hop, the ForCES
protocol will make use of an existing RFC2914 compliant L4 protocol
Khosravi, et. al. Expires November 2003 [Page 11]
Internet Draft ForCES Requirements May 2003
with adequate reliability, security and congestion control (e.g.
TCP, SCTP) for transport purposes.
5)Message Priority
The ForCES protocol MUST provide a means to express the protocol
message priorities.
6)Reliability
a) The ForCES protocol will be used to transport information that
requires varying levels of reliability. By strict or robust
reliability in this requirement we mean, no losses, no corruption,
no re-ordering of information being transported and delivery in a
timely fashion.
b) Some information or payloads, such as redirected packets or packet
sampling, may not require robust reliability (can tolerate some
degree of losses). For information of this sort, ForCES MAY NOT
impose strict reliability.
c) Payloads such as configuration information, e.g. ACLs, FIB
entries, or FE capability information (described in section 7,
(1)) are mission critical and must be delivered in a robust
reliable fashion. Thus, for information of this sort, ForCES MUST
either provide built-in protocol mechanisms or use a reliable
transport protocol for achieving robust/strict reliability.
d) Some information or payloads, such as heartbeat packets that may
be used to detect loss of association between CE and FEs (see
section 7, (8)), may prefer timeliness over reliable delivery. For
information of this sort, ForCES MAY NOT impose strict
reliability.
e) When ForCES is carried over multi-hop IP networks, it is a
requirement that ForCES MUST use a [RFC2914]-compliant transport
protocol.
f) In cases where ForCES is not running over an IP network such as an
Ethernet or cell fabric between CE and FE, then reliability still
MUST be provided when carrying critical information of the types
specified in (c) above, either by the underlying link/network/
transport layers or by built-in protocol mechanisms.
7)Interconnect Independence
The ForCES protocol MUST support a variety of interconnect
technologies. (refer to section 5, requirement# 1)
8)CE redundancy or CE failover
The ForCES protocol MUST support mechanisms for CE redundancy or CE
failover. This includes the ability for CEs and FEs to determine
when there is a loss of association between them, ability to restore
association and efficient state (re)synchronization mechanisms. This
also includes the ability to preset the actions an FE will take in
reaction to loss of association to its CE e.g., whether the FE will
Khosravi, et. al. Expires November 2003 [Page 12]
Internet Draft ForCES Requirements May 2003
continue to forward packets or whether it will halt operations.
(refer to section 5, requirement# 7)
9)Packet Redirection/Mirroring
a) The ForCES protocol MUST define a way to redirect packets from the
FE to the CE and vice-versa. Packet redirection terminates any
further processing of the redirected packet at the FE.
b) The ForCES protocol MUST define a way to mirror packets from the
FE to the CE. Mirroring allows the packet duplicated by the FE at
the mirroring point to be sent to the CE while the original packet
continues to be processed by the FE.
Examples of packets that may be redirected or mirrored include
control packets (such as RIP, OSPF messages) addressed to the
interfaces or any other relevant packets (such as those with Router
Alert Option set). The ForCES protocol MUST also define a way for the
CE to configure the behavior of a) and b) (above), to specify which
packets are affected by each.
10)Topology Exchange
The ForCES protocol MUST allow the FEs to provide their topology
information (topology by which the FEs in the NE are connected) to
the CE(s). (refer to section 5, requirement# 10)
11)Dynamic Association
The ForCES protocol MUST allow CEs and FEs to join and leave a NE
dynamically. (refer to section 5, requirement# 12)
12)Command Bundling
The ForCES protocol MUST be able to group an ordered set of commands
to a FE. Each such group of commands SHOULD be sent to the FE in as
few messages as possible. Furthermore, the protocol MUST support the
ability to specify if a command group MUST have all-or-nothing
semantics.
13)Asynchronous Event Notification
The ForCES protocol MUST be able to asynchronously notify the CE of
events on the FE such as failures or change in available resources
or capabilities. (refer to section 5, requirement# 6)
14)Query Statistics
The ForCES protocol MUST provide a means for the CE to be able to
query statistics (monitor performance) from the FE.
15) Protection against Denial of Service Attacks (based on CPU
overload or queue overflow)
Systems utilizing the ForCES protocol can be attacked using denial
of service attacks based on CPU overload or queue overflow.
The ForCES protocol could be exploited by such attacks to cause the
CE to become unable to control the FE or appropriately communicate
Khosravi, et. al. Expires November 2003 [Page 13]
Internet Draft ForCES Requirements May 2003
with other routers and systems. The ForCES protocol MUST therefore
provide mechanisms for controlling FE capabilities that can be used
to protect against such attacks. FE capabilities that MUST be
manipulated via ForCES include the ability to install classifiers
and filters to detect and drop attack packets, as well as to be able
to install rate limiters that limit the rate of packets which appear
to be valid but may be part of an attack (e.g. bogus BGP packets).
8. References
8.1.Normative References
[RFC3290] Y. Bernet, et. al., "An Informal Management Model for
DiffServ Routers", , May 2002.
[RFC1812] F. Baker, "Requirements for IP Version 4 Routers",
RFC1812, June 1995.
[RFC2211] J. Wroclawski, "Specification of the Controlled-Load
Network Element Service", RFC2211, September 1997.
[RFC2212] S. Shenker, C. Partridge, R. Guerin, "Specification of
Guaranteed Quality of Service", RFC2212, September 1997.
[RFC2215] S. Shenker, J. Wroclawski, "General Characterization
Parameters for Integrated Service Network Elements", RFC2215,
September 1997.
[RFC2475] S. Blake, et. Al., "An Architecture for Differentiated
Service", RFC2475, December 1998.
[RFC2914] S. Floyd, "Congestion Control Principles", RFC2914,
September 2000.
[RFC2663] P. Srisuresh & M. Holdrege, "IP Network Address
Translator (NAT) Terminology and Considerations", RFC2663, August
1999.
8.2.Informative References
[REQ-PART] T. Anderson, J. Buerkle, "Requirements for the Dynamic
Partitioning of Switching Elements", work in progress, July 2002,
<draft-ietf-gsmp-dyn-part-reqs-02.txt>.
[IPFLOW] Quittek, et. Al., "Requirements for IP Flow Information
Export", work in progress, February 2003, <draft-ietf-ipfix-reqs-
09.txt>.
Khosravi, et. al. Expires November 2003 [Page 14]
Internet Draft ForCES Requirements May 2003
[PSAMP] Duffield, et. Al., "A Framework for Passive Packet
Measurement ", work in progress, March 2003, <draft-ietf-psamp-
framework-02.txt>.
9. Security Considerations
See architecture requirement #5 and protocol requirement #2.
10. Authors' Addresses & Acknowledgments
This document was written by the ForCES Requirements design team:
Todd A. Anderson (Editor)
Ed Bowen
IBM Zurich Research Laboratory
Saumerstrasse 4
CH-8803 Rueschlikon Switzerland
Phone: +41 1 724 83 68
Email: edbowen@us.ibm.com
Ram Dantu
Department of Computer Science
University of North Texas,
Denton, Texas, 76203
Email: rdantu@unt.edu
Phone: 940 565 2822
Avri Doria
Institute for System Technology
Lulea University of Technology
SE-971 87, Lulea, Sweden
Phone: +46 (0)920 49 3030
Email: avri@sm.luth.se
Ram Gopal
Nokia Research Center
5, Wayside Road,
Burlington, MA 01803
Phone: 1-781-993-3685
Email: ram.gopal@nokia.com
Jamal Hadi Salim
Znyx Networks
Ottawa, Ontario
Canada
Email: hadi@znyx.com
Khosravi, et. al. Expires November 2003 [Page 15]
Internet Draft ForCES Requirements May 2003
Hormuzd Khosravi (Editor)
Muneyb Minhazuddin
Avaya Inc.
123, Epping road,
North Ryde, NSW 2113, Australia
Phone: +61 2 9352 8620
email: muneyb@avaya.com
Margaret Wasserman
Wind River
10 Tara Blvd., Suite 330
Nashua, NH 03062
Phone: +1 603 897 2067
Email: mrw@windriver.com
The authors would like to thank Vip Sharma and Lily Yang for their
valuable contributions.
11. Editors' Contact Information
Hormuzd Khosravi
Intel
2111 NE 25th Avenue
Hillsboro, OR 97124 USA
Phone: +1 503 264 0334
Email: hormuzd.m.khosravi@intel.com
Todd A. Anderson
Intel
2111 NE 25th Avenue
Hillsboro, OR 97124 USA
Phone: +1 503 712 1760
Email: todd.a.anderson@intel.com
Khosravi, et. al. Expires November 2003 [Page 16]| PAFTECH AB 2003-2026 | 2026-04-24 02:47:57 |