Yang Data Model for Service Function Chaining Control Plane
draft-shin-sfc-control-plane-yang-00
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|---|---|---|---|
| Authors | Myung-Ki Shin , Mi-Jung Choi , Seungik Lee | ||
| Last updated | 2015-10-19 | ||
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draft-shin-sfc-control-plane-yang-00
Internet Engineering Task Force (IETF) M-K. Shin
Internet-Draft ETRI
Intended status: Informational M-J. Choi
Expires: April 21, 2016 KNU
S. Lee
ETRI
October 19, 2015
Yang Data Model for Service Function Chaining Control Plane
draft-shin-sfc-control-plane-yang-00
Abstract
This document defines Yang data model for control plane management of
service function chaining based on [I-D.ietf-sfc-control-plane],
which describes components and requirements of SFC control plane.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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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."
This Internet-Draft will expire on April 21, 2016.
Copyright Notice
Copyright (c) 2015 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Overall Module Structure . . . . . . . . . . . . . . . . . . 4
3.1. SFC-Control-Planes Configuration Model . . . . . . . . . 4
4. Path Maintenance . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Path Maintenance Configuration Model . . . . . . . . . . 6
5. Path Optimization . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Path Optimization Configuration Model . . . . . . . . . . 7
6. Load Balancing . . . . . . . . . . . . . . . . . . . . . . . 8
6.1. Load Balancing Configuration Model . . . . . . . . . . . 8
7. SFC Topology . . . . . . . . . . . . . . . . . . . . . . . . 10
7.1. SFC Topology Configuration Model . . . . . . . . . . . . 10
8. Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1. Policy Configuration Model . . . . . . . . . . . . . . . 12
9. History . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1. History Configuration Model . . . . . . . . . . . . . . . 14
10. Fault Handling . . . . . . . . . . . . . . . . . . . . . . . 17
10.1. Fault Handling Configuration Model . . . . . . . . . . . 17
11. Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.1. Event Configuration Model . . . . . . . . . . . . . . . 19
12. Security Considerations . . . . . . . . . . . . . . . . . . . 19
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
14.1. Normative References . . . . . . . . . . . . . . . . . . 20
14.2. Informative References . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
1. Introduction
Service Function Chaining (SFC) consists of SFC data plane and
control plane from the aspect of architecture
[I-D.ietf-sfc-architecture]. The document
[I-D.ietf-sfc-control-plane] describes requirements for delivering
information between SFC control elements and SFC functional elements.
By capturing the information conveyed via a set of control interfaces
in [I-D.ietf-sfc-control-plane], this document defines Yang data
model of management operations performed in a SFC control plane.
Note that the base Yang data model for the SFC data plane is already
covered in [I-D.penno-sfc-yang].
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2. Terminology
This document uses the following terms and most of them were
reproduced from [I-D.ietf-sfc-architecture] and
[I-D.ietf-sfc-control-plane].
o Classification: Locally instantiated policy and customer/network/
service profile matching of traffic flows for identification of
appropriate outbound forwarding actions.
o Service Function Chain (SFC): A service function chain defines a
set of abstract service functions and ordering constraints that
must be applied to packets and/or frames selected as a result of
classification. The implied order may not be a linear progression
as the architecture allows for SFCs that copy to more than one
branch, and also allows for ere there is flexibility in the order
in which service functions need to be applied. The term service
chain is often used as shorthand for service function chain.
o Service Function (SF): A function that is responsible for specific
treatment of received packets. A Service Function can act at
various layers of a protocol stack (e.g., at the network layer or
other OSI layers). As a logical component, a Service Function can
be realized as a virtual element or be embedded in a physical
network element. One or multiple Service Functions can be
embedded in the same network element. Multiple occurrences of the
Service Function can exist in the same administrative domain.
o Service Function Instance (SFI): The instantiation of Service
Function that can be a virtual instance or be embedded in a
physical network element. One of multiple Service Functions can
be embedded in the same network element. Multiple instances of
the Service Function can be enabled in the same administrative
domain.
o Service Function Forwarder (SFF): A service function forwarder is
responsible for delivering traffic received from the network to
one or more connected service functions according to information
carried in the SFC encapsulation, as well as handling traffic
coming back from the SF. Additionally, a service function
forwarder is responsible for delivering traffic to a classifier
when needed and supported, mapping out traffic to another SFF (in
the same or different type of overlay), and terminating the SFP.
o Service Function Path (SFP): The SFP provides a level of
indirection between the fully abstract notion of service chain as
a sequence of abstract service functions to be delivered, and the
fully specified notion of exactly which SFF/SFs the packet will
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visit when it actually traverses the network. By allowing the
control components to specify this level of indirection, the
operator may control the degree of SFF/SF selection authority that
is delegated to the network.
3. Overall Module Structure
Ahead to defining separate sub-modules, overall module structure for
the management of SFC control plane is examined. The overall modules
consist of 8 sub-modules (groups). The overall module is devised on
the basis of the requirements for conveying information between SFC
control elements and SFC functional elements described in the
document [I-D.ietf-sfc-control-plane].
Module: SFC-control-planes
o Path Maintenance
o Path Optimization
o Load Balancing
o SFC Topology
o Policy
o History
o Fault Handling
o Event
3.1. SFC-Control-Planes Configuration Model
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module sfc-control-planes {
namespace "urn:etri:params:xml:ns:yang:sfc-cp";
prefix sfc-cp;
include path-maintenance {
revision-date 2015-10-15;
}
include path-optimization {
revision-date 2015-10-15;
}
include load-balancing {
revision-date 2015-10-15;
}
include sfc-topology {
revision-date 2015-10-15;
}
include policy {
revision-date 2015-10-15;
}
include history {
revision-date 2015-10-15;
}
include fault-handling {
revision-date 2015-10-15;
}
include event {
revision-date 2015-10-15;
}
organization "ETRI.";
contact
"M-K. Shin mkshin@etri.re.kr
M-J Choi mjchoi@kangwon.ac.kr";
revision-date 2015-10-15;
}
4. Path Maintenance
This module checks the aliveness of a SFP. This receives SFP name
and returns aliveness result which is true or false value.
o SFP name
o Aliveness of SFP: True or False
o RPC: check-path-aliveness (input: SFP name, output: aliveness)
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4.1. Path Maintenance Configuration Model
submodule path-maintenance {
belongs-to sfc-control-planes {
prefix sfc-pm;
}
description
"This module checks the aliveness of a SFP. This receives SFP
name and returns aliveness result which is true or false value."
revision 2015-10-15;
container path-maintenance {
leaf sfp-name {
type string;
description
"The name of service function path.";
}
leaf aliveness-of-sfp {
type boolean;
description
"Aliveness flag of the service function.";
}
}
rpc check-path-aliveness {
description "Check a path aliveness.";
input {
leaf sfc-name {
type string;
description
"The name of service function path.";
}
}
output {
leaf aliveness {
type boolean;
description
"Aliveness flag of the service function.";
}
}
}
}
5. Path Optimization
This module constructs and maintains a SFP with a low stretch
considering the topological locations and properties (e.g., latency,
bandwidth) of SFI
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o SFP name
o Optimized SFP
o SFP availability
o Load status
o RPC: Find-optimized-SFP (input: SFP name, output: optimized SFP,
SFP availability, Load status)
5.1. Path Optimization Configuration Model
submodule path-optimization {
belongs-to sfc-control-planes {
prefix sfc-po;
}
description
"This module constructs and maintains a SFP with a low stretch
considering the topological locations and properties (e.g.,
latency, bandwidth) of SF.";
revision 2015-10-15;
container path-optimization {
leaf sfp-name {
type string;
description
"The name of service function path to be changed for
optimization.";
}
leaf optimized-sfp {
type string;
description
"The name of optimized service function path.";
}
leaf sfp-availability {
type boolean;
description
"The availability of the optimized service function path:
true or false.";
}
leaf load-status {
type uint8;
description
"A percentage value of load status.";
}
}
rpc find-optimized-sfp {
description
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"Find an optimized service function path.";
input {
leaf sfp-name {
type string;
description
"The name of service function path to be changed for
optimization.";
}
}
output {
leaf optimized-sfp {
type string;
description
"The name of optimized service function path.";
}
leaf sfp-availability {
type string;
description
"The availability of the optimized service function path:
true or false.";
}
}
}
}
6. Load Balancing
This module constructs and maintains SFPs to localize the traffic in
the network considering load and administrative domain of SFIs.
o Load type: traffic/CPU/memory
o Source SFP name
o Target SFP name
o RPC: perform-load-balance (input: Load type, source SFP name,
output: target SFP name)
6.1. Load Balancing Configuration Model
submodule load-balancing {
belongs-to sfc-control-planes{
prefix sfc-lb;
}
description
"This module constructs and maintains SFPs to localize the
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traffic in the network considering load and administrative
domain of SFIs.";
revision 2015-10-15;
container load-balancing {
leaf load-type {
type enumeration {
enum traffic;
enum cpu;
enum memory;
}
description
"A resource type for load balancing.";
}
leaf source-sfp-name {
type string;
description
"The name of service function path with heavy load.";
}
leaf target-sfp-name {
type string;
description
"Another name of service function path for load
distribution.";
}
}
rpc perform-load-balance {
description
"Perform a load balancing.";
input {
leaf load-type {
type enumeration {
enum traffic;
enum cpu;
enum memory;
}
description
"A resource type for load balancing.";
}
leaf source-sfp-name {
type string;
description
"The name of service function path with heavy load.";
}
}
output {
leaf target-sfp-name {
type string;
description
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"Another name of service function path for load
distribution.";
}
}
}
}
7. SFC Topology
This module shows the connectivity map of currently working SFCs,
SFPs and SFIs.
o Name: SFC name or SFP name or SFI name
o Lists of SF node
o RPC: show-SFC-topology (input: SFC name, output: list of SF nodes)
7.1. SFC Topology Configuration Model
submodule sfc-topology {
belongs-to sfc-control-planes {
prefix sfc-st;
}
description
"This module shows the connectivity map of currently working
SFCs, SFPs and SFIs.";
revision 2015-10-15;
container sfc-topology {
leaf name {
type string;
description
"The name of service function chain or service function
path or service function instances.";
}
list lists-of-sf-node {
key name;
description
"A list of service functions that compose the service
chain.";
leaf name {
type string;
description
"A list of service functions that compose the service
chain.";
}
leaf order {
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type uint8;
description
"The order of the service functions.";
}
}
}
rpc show-sfc-topology {
description
"Display the topology of service function chain.";
input {
leaf sfc-name {
type string;
description
"The name of service function chain.";
}
}
output {
list lists-of-sf-node {
key name;
description
"A list of service functions that compose the service
chain.";
leaf name {
type string;
description
"A list of service functions that compose the service
chain.";
}
leaf order {
type uint8;
description
"The order of the service functions.";
}
}
}
}
}
8. Policy
Policies are used to bind an incoming flow to an appropriate SFP.
o Classification Policy Table: One SFC is selected by a
classification function according to the defined policy. The
classification means service profile matching of traffic flows for
identification of appropriate outbound forwarding actions.
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* Flow identifier
* Matching condition
* Priority
* Mapping SFC name
o Forwarding Policy Table: This policy is used to select SFIs
defined in SFC and connect them. A SFF is responsible for
delivering traffic received from the network to one or more
connected service functions according to the policy table.
* SFF name
* Condition
* SFC name
* SFP name
8.1. Policy Configuration Model
submodule policy {
belongs-to sfc-control-planes {
prefix sfc-p;
}
description
"Policies are used to bind an incoming flow to an appropriate
SFP.";
revision 2015-10-15;
container classification-policy-table {
description
"One SFC is selected by classification function according to
the defined policy. The classification means service profile
matching of traffic flows for identification of appropriate
outbound forwarding actions.";
list classification-policy-table {
key flow-identifier;
description
"To classify the flow, flow identification is necessary.";
leaf flow-identifier {
type string;
description
"The flow identifier.";
}
leaf matching-condition {
type string;
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description
"The flow matching condition.";
}
leaf priority {
type int32;
description
"Policy priority. The low value is high priority.";
}
leaf mapping-sfc-name {
type string;
description
"The mapped service function name of the flow.";
}
}
}
container forwarding-policy-table {
description
"This policy is used to select SFIs defined in SFC and
connect them. This policy is used in Service Function
Forwarder (SFF). A SFF is responsible for delivering traffic
received from the network to one or more connected service
functions according to the policy table.";
list Forwarding-Policy-Table {
key index;
description
"The index of forwarding policy table.";
leaf index {
type int32;
description
"The index of forwarding policy table.";
}
leaf sff-name {
type string;
description
"The name of service function forwarder.";
}
leaf sfc-name {
type string;
description
"The name of service function chain.";
}
leaf condition {
type string;
description
"The mapping condition.";
}
leaf sfp-name {
type string;
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description
"The name of service function path.";
}
}
}
}
9. History
This module shows statistical information related performance and
faults in accordance with SFCs and SFPs.
o Performance: it monitors and stores time series data related
performance
* Name: SFC name or SFP name
* Time
* Aliveness
* Resource utilization: packet-rate, bandwidth, CPU usage, memory
usage, available memory, RIB, FIB, SF-ports bandwidth
o Fault: it monitors and stores time series data related to faults
and events.
* Fault name
* Fault occurrence time
* Fault type
* Fault occurrence location
* Fault handling action
9.1. History Configuration Model
submodule history {
belongs-to sfc-control-planes {
prefix sfc-h;
}
import ietf-yang-types {
prefix yang;
revision-date 2013-07-15;
}
description
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"This module shows statistical information related performance
and faults in accordance with SFCs and SFPs."
revision 2015-10-15;
container performance {
description
"It monitors and stores time series data related performance."
list Performance {
key name
description
"The name of service function.";
leaf name {
type string;
description
"The name of service function.";
}
leaf time {
type yang:date-and-time;
description
"The performance monitoring date.";
}
leaf aliveness {
type Boolean;
description
"The aliveness flag of the service function.";
}
container resource-utilization {
description
"To be defined.";
leaf packet-rate {
type uint8;
description
"Percentage of current package rate utilization.";
}
leaf bandwidth {
type uint8;
description
"Percentage of bandwidth utilization.";
}
leaf cpu-usage {
type uint8;
description
"Percentage of CPU utilization.";
}
leaf memory-usage {
type uint8;
description
"Percentage of memory utilization.";
}
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leaf available-memory {
type uint8;
description
"Available memory size of the service function in MB.";
}
leaf rib {
type uint8;
description
"Percentage of Routing Information Table utilization.";
}
leaf fib {
type uint8;
description
"Percentage of Forwarding Information Table
utilization.";
}
leaf sf-ports-bandwidth {
type uint8;
description
"Percentage of the port's supported bandwidth
utilization.";
}
}
}
}
container fault {
description
"It monitors and stores time series data related to faults
and events."
list fault {
key fault-name;
description
"The name occurred fault.";
leaf fault-name {
type string;
description
"The name occurred fault.";
}
leaf fault-occurrence-time {
type yang:date-and-time;
description
"The time of the fault occurrence.";
}
leaf fault-type {
type string;
description
"The type of occurred fault.";
}
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leaf fault-occurrence-location {
type string;
description
"The location of fault occurrence.";
}
leaf fault-handling-action {
type string;
description
"The fault handing action: drop, bypass, use alternate
node.";
}
}
}
}
10. Fault Handling
This module first detects faults and handles the detected faults in
accordance with the fault handling action.
o Fault name: Key
o Fault type: Node/Link/Path failures
o Fault handing action: Bypass/Use alternate node/Use alternate
chain/Drop traffic
o RPC: handle-fault (input: fault name, output: fault handle result)
10.1. Fault Handling Configuration Model
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submodule fault-handling {
belongs-to sfc-control-planes {
prefix sfc-fh
}
description
"This module first detects faults and handles the detected
faults in accordance with the fault handling action. ";
revision 2015-10-15;
container fault-handling {
list fault-handling {
key fault-name;
description
"The name of occurred fault.";
leaf fault-name {
type string;
description
"The fault handing action: drop, bypass, use alternate
node.";
}
leaf fault-type {
type enumeration {
enum node;
enum link;
enum path-failures;
}
description
"The type of occurred fault.";
}
leaf fault-handling-action
type enumeration {
enum bypass;
enum use-alternate-node;
enum use-alternate-chain;
enum drop-traffic;
}
description
"The fault handing action: drop, bypass, use alternate
node.";
}
}
}
}
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11. Event
Events such as loops detection, long unavailable forwarding path
time, out of service of SFIs are defined.
11.1. Event Configuration Model
submodule event {
belong-to sfc-control-planes {
prefix sfc-e;
}
revision 2015-10-15;
notification event {
description
"Events such as loops detection, long unavailable forwarding
path time, out of service of SFIs.";
leaf event-type {
type string;
description
"Event type.";
}
leaf severity {
type string;
description
"The severity of the event.";
}
leaf event-explanation {
type string;
description
"The detailed explanation of the event.";
}
}
}
12. Security Considerations
TBD.
13. IANA Considerations
TBD.
14. References
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14.1. 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>.
14.2. Informative References
[I-D.ietf-sfc-architecture]
Halpern, J. and C. Pignataro, "Service Function Chaining
(SFC) Architecture", draft-ietf-sfc-architecture-11 (work
in progress), July 2015.
[I-D.ietf-sfc-control-plane]
Li, H., Wu, Q., Huang, O., Boucadair, M., Jacquenet, C.,
Haeffner, W., Lee, S., Parker, R., Dunbar, L., Malis, A.,
Halpern, J., Reddy, T., and P. Patil, "Service Function
Chaining (SFC) Control Plane Components & Requirements",
draft-ietf-sfc-control-plane-00 (work in progress), August
2015.
[I-D.lee-sfc-dynamic-instantiation]
Lee, S., Pack, S., Shin, M., and E. Paik, "SFC dynamic
instantiation", draft-lee-sfc-dynamic-instantiation-01
(work in progress), October 2014.
[I-D.penno-sfc-yang]
Penno, R., Quinn, P., Zhou, D., and J. Li, "Yang Data
Model for Service Function Chaining", draft-penno-sfc-
yang-13 (work in progress), March 2015.
Authors' Addresses
Myung-Ki Shin
ETRI
218 Gajeong-ro Yuseung-Gu
Daejeon 305-700
Korea
Phone: +82 42 860 4847
Email: mkshin@etri.re.kr
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Mi-Jung Choi
Kangwon National University
1 Kangwondaehak-gil
Chuncheon-si, Gangwon-do 24341
Korea
Phone: +82 33 250 8442
Email: mjchoi@kangwon.ac.kr
Seungik Lee
ETRI
218 Gajeong-ro Yuseung-Gu
Daejeon 305-700
Korea
Phone: +82 42 860 1483
Email: seungiklee@etri.re.kr
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