SFC Netmod R. Penno
Internet-Draft P. Quinn
Intended status: Standards Track Cisco Systems
Expires: April 26, 2015 October 23, 2014
Yang Data Model for Service Function Chaining
draft-penno-sfc-yang-08
Abstract
This document defines a YANG data model that can be used to configure
and manage Service Function Chains.
Requirements Language
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].
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
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
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 26, 2015.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
Penno & Quinn Expires April 26, 2015 [Page 1]
Internet-Draft Yang Model for Service Chaining October 2014
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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Definitions and Acronyms . . . . . . . . . . . . . . . . . . 3
3. Service Function (SF) . . . . . . . . . . . . . . . . . . . . 3
3.1. Module Structure . . . . . . . . . . . . . . . . . . . . 3
3.2. Service Function . . . . . . . . . . . . . . . . . . . . 4
4. Service Function Type (SFT) . . . . . . . . . . . . . . . . . 9
4.1. Module Structure . . . . . . . . . . . . . . . . . . . . 9
4.2. Service Function Type Configuration Model . . . . . . . . 9
5. Service Function Chain (SFC) . . . . . . . . . . . . . . . . 11
5.1. Module Structure . . . . . . . . . . . . . . . . . . . . 12
5.2. Service Function Chain Configuration Model . . . . . . . 12
6. Service Node (SN) . . . . . . . . . . . . . . . . . . . . . . 16
6.1. Module Structure . . . . . . . . . . . . . . . . . . . . 16
6.2. Service Node Configuration Model . . . . . . . . . . . . 16
7. Service Function Path (SFP) . . . . . . . . . . . . . . . . . 18
7.1. Module Structure . . . . . . . . . . . . . . . . . . . . 19
7.2. Service Function Path Configuration Model . . . . . . . . 19
8. Service Function Forwarder (SFF) . . . . . . . . . . . . . . 22
8.1. Module Struture . . . . . . . . . . . . . . . . . . . . . 22
8.2. Service Function Forwarder Model . . . . . . . . . . . . 23
9. Service Function Forwarder Open vSwitch (SFF-OVS) . . . . . . 27
9.1. Module Struture . . . . . . . . . . . . . . . . . . . . . 27
9.2. Service Function Forwarder OVS Model . . . . . . . . . . 27
10. Service Locator (SL) . . . . . . . . . . . . . . . . . . . . 29
10.1. Module Structure . . . . . . . . . . . . . . . . . . . . 29
10.2. Service Locator Module . . . . . . . . . . . . . . . . . 29
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32
12. Security Considerations . . . . . . . . . . . . . . . . . . . 32
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 32
14. Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 34
15.1. Normative References . . . . . . . . . . . . . . . . . . 34
15.2. Informative References . . . . . . . . . . . . . . . . . 35
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 35
1. Introduction
YANG [RFC6020] is a data definition language that was introduced to
define the contents of a conceptual data store that allows networked
devices to be managed using NETCONF [RFC6241]. YANG is proving
relevant beyond its initial confines, as bindings to other interfaces
(e.g. ReST) and encodings other than XML (e.g. JSON) are being
Penno & Quinn Expires April 26, 2015 [Page 2]
Internet-Draft Yang Model for Service Chaining October 2014
defined. Furthermore, YANG data models can be used as the basis of
implementation for other interfaces, such as CLI and programmatic
APIs.
This document defines a YANG data model that can be used to configure
and manage Service Function Chains
2. Definitions and Acronyms
The reader should be familiar with the terms contained in
[I-D.quinn-sfc-arch], [I-D.ietf-sfc-problem-statement]
,[I-D.quinn-sfc-nsh] and [I-D.quinn-vxlan-gpe]
3. Service Function (SF)
This module describe a Service Function, which is an essential
building block of other modules.
3.1. Module Structure
module: service-function
+--rw service-functions
| +--rw service-function* [name]
| +--rw name string
| +--rw type string
| +--rw ip-mgmt-address? inet:ip-address
| +--rw nsh-aware? boolean
| +--rw sf-data-plane-locator* [name]
| +--rw name string
| +--rw (locator-type)
| | +--:(ip)
| | | +--rw ip? inet:ip-address
| | | +--rw port? inet:port-number
| | +--:(lisp)
| | | +--rw eid? inet:ip-address
| | +--:(mac)
| | +--rw mac? yang:mac-address
| | +--rw vlan-id? uint16
| +--rw transport? identityref
| +--rw service-function-forwarder? string
+--ro service-functions-state
+--ro service-function-state* [name]
+--ro name string
+--ro sf-service-function-path* string
rpcs:
+---x delete-all-service-function
+---x put-service-function
| +--ro input
Penno & Quinn Expires April 26, 2015 [Page 3]
Internet-Draft Yang Model for Service Chaining October 2014
| +--ro name? string
| +--ro type string
| +--ro ip-mgmt-address? inet:ip-address
| +--ro nsh-aware? boolean
| +--ro sf-data-plane-locator* [name]
| +--ro name string
| +--ro (locator-type)
| | +--:(ip)
| | | +--ro ip? inet:ip-address
| | | +--ro port? inet:port-number
| | +--:(lisp)
| | | +--ro eid? inet:ip-address
| | +--:(mac)
| | +--ro mac? yang:mac-address
| | +--ro vlan-id? uint16
| +--ro transport? identityref
| +--ro service-function-forwarder? string
+---x read-service-function
| +--ro input
| | +--ro name string
| +--ro output
| +--ro name? string
| +--ro type string
| +--ro ip-mgmt-address? inet:ip-address
| +--ro nsh-aware? boolean
| +--ro sf-data-plane-locator* [name]
| +--ro name string
| +--ro (locator-type)
| | +--:(ip)
| | | +--ro ip? inet:ip-address
| | | +--ro port? inet:port-number
| | +--:(lisp)
| | | +--ro eid? inet:ip-address
| | +--:(mac)
| | +--ro mac? yang:mac-address
| | +--ro vlan-id? uint16
| +--ro transport? identityref
| +--ro service-function-forwarder? string
+---x delete-service-function
+--ro input
+--ro name string
3.2. Service Function
file "service-function@2014-07-01.yang"
module service-function {
Penno & Quinn Expires April 26, 2015 [Page 4]
Internet-Draft Yang Model for Service Chaining October 2014
namespace "urn:cisco:params:xml:ns:yang:sfc-sf";
prefix sfc-sf;
import ietf-inet-types { prefix inet; }
import ietf-yang-types { prefix yang; }
import service-function-type {prefix sfc-sft;}
import service-locator {prefix sfc-sl;}
organization "Cisco Systems, Inc.";
contact "Reinaldo Penno ";
description
"This module contains a collection of YANG definitions for
managing service function.
It follows closely the constructs of
http://tools.ietf.org/html/draft-ietf-netmod-interfaces-cfg-12
Copyright (c) 2013 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-07-01 {
description
"Changes based on Opendaylight Testing.";
}
typedef service-function-ref {
type leafref {
path "/sfc-sf:service-functions/sfc-sf:service-function/"
Penno & Quinn Expires April 26, 2015 [Page 5]
Internet-Draft Yang Model for Service Chaining October 2014
+ "sfc-sf:name";
}
description
"This type is used by data models that need to reference
configured service functions.";
}
grouping service-function-entry {
description
"This group bundles together all information related to a
single service function";
leaf name {
type string;
description
"The name of the service function.";
}
leaf type {
type string;
mandatory true;
description
"Service Function Type from service-function-type yang
model";
}
leaf ip-mgmt-address {
type inet:ip-address;
description
"The IP and port used to configure this service-node";
}
leaf nsh-aware {
type boolean;
description "Whether this SF can process NSH headers";
}
list sf-data-plane-locator {
description
"A network data-plane locator";
key "name";
leaf name {
type string;
description
"A unique string that represents this
data-plane-locator";
}
uses sfc-sl:data-plane-locator;
leaf service-function-forwarder {
type string;
description
"The service function forwarder associated with this
Penno & Quinn Expires April 26, 2015 [Page 6]
Internet-Draft Yang Model for Service Chaining October 2014
locator";
}
}
}
container service-functions {
description
"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). A Service Function can be a virtual
element or be embedded in a physical network element. One of
multiple Service Functions can be embedded in the same network
element. Multiple occurrences of the Service Function can be
enabled in the same administrative domain.
One or more Service Functions can be involved in the delivery
of added-value services. A non-exhaustive list of Service
Functions includes: firewalls, WAN and application
acceleration, Deep Packet Inspection (DPI),a LI (Lawful
Intercept) module, server load balancers, NAT44 [RFC3022],
NAT64 [RFC6146], NPTv6 [RFC6296], HOST_ID injection, HTTP
Header Enrichment functions, TCP optimizer, etc.
An SF may be SFC encapsulation aware, that is it receives, and
acts on information in the SFC encapsulation, or unaware in
which case data forwarded to the service does not contain the
SFC encapsulation.";
list service-function {
description
"This list holds configuration data for all service functions
in the domain";
key "name";
uses service-function-entry;
}
}
container service-functions-state {
description
"This container hold operational state for all service
functions";
config false;
list service-function-state {
description
"This list holds operational data for all service functions
in the domain";
key "name";
Penno & Quinn Expires April 26, 2015 [Page 7]
Internet-Draft Yang Model for Service Chaining October 2014
leaf name {
type string;
description
"the name of the service function";
}
leaf-list sf-service-function-path {
type string;
description
"A list of all service function paths that contain this
service function";
}
}
}
rpc delete-all-service-function {
description
"Deletes all service functions";
}
rpc put-service-function {
description
"Creates a service function";
input {
uses service-function-entry;
}
}
rpc read-service-function {
description
"Reads a service function";
input {
leaf name {
type string;
mandatory true;
description "The name of the service function.";
}
}
output {
uses service-function-entry;
}
}
rpc delete-service-function {
description
"Deletes a service function";
input {
leaf name {
type string;
mandatory true;
description "The name of the service function.";
Penno & Quinn Expires April 26, 2015 [Page 8]
Internet-Draft Yang Model for Service Chaining October 2014
}
}
}
}
4. Service Function Type (SFT)
4.1. Module Structure
module: service-function-type
+--rw service-function-types
+--rw service-function-type* [type]
+--rw type string
+--rw sft-service-function-name* [name]
+--rw name string
4.2. Service Function Type Configuration Model
file "service-function-type@2014-07-01.yang"
module service-function-type {
namespace "urn:cisco:params:xml:ns:yang:sfc-sft";
prefix sfc-sft;
import ietf-inet-types { prefix inet; }
import ietf-yang-types { prefix yang; }
organization "Cisco Systems, Inc.";
contact "Reinaldo Penno ";
description
"This module contains a collection of YANG definitions for
managing service function types.
It follows closely the constructs of
http://tools.ietf.org/html/draft-ietf-netmod-interfaces-cfg-12
Copyright (c) 2013 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Penno & Quinn Expires April 26, 2015 [Page 9]
Internet-Draft Yang Model for Service Chaining October 2014
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-07-01 {
description
"Changes based on Opendaylight Testing.";
}
// Service Function
// Service Function Type definitions
identity service-function-type-identity {
description
"Base identity from which specific service function
types are derived.";
}
identity firewall {
base "service-function-type-identity";
description "Firewall";
}
identity dpi {
base "service-function-type-identity";
description "Deep Packet Inspection";
}
identity napt44 {
base "service-function-type-identity";
description "Network Address and Port Translation 44";
}
typedef service-function-type {
Penno & Quinn Expires April 26, 2015 [Page 10]
Internet-Draft Yang Model for Service Chaining October 2014
type identityref {
base "service-function-type-identity";
}
description "This type is used to reference all
registered service function types";
}
container service-function-types {
description
"A list of Service function Types. For each type we keep
a list of Service Functions";
list service-function-type {
key "type";
leaf type {
type string;
description
"The service function type";
}
list sft-service-function-name {
key "name";
leaf name {
type string;
description
"The name of the service function.";
}
description
"The list of all service functions of a specific type";
}
description
"A list of all service types. Each service-type entry holds
a list of all service functions of the type";
}
}
}
5. Service Function Chain (SFC)
This model describes a service function chain which is basically an
ordered list of services. But a service function chain does not
specify exactly which service (firewal1 vs. firewall2) will be used
to actually process packets.
Penno & Quinn Expires April 26, 2015 [Page 11]
Internet-Draft Yang Model for Service Chaining October 2014
5.1. Module Structure
module: service-function-chain
+--rw service-function-chains
| +--rw service-function-chain* [name]
| +--rw name string
| +--rw symmetric? boolean
| +--rw sfc-service-function* [name]
| +--rw name string
| +--rw type string
+--ro service-function-chains-state
+--ro service-function-chain-state* [name]
+--ro name string
+--ro sfc-service-function-path* string
rpcs:
+---x instantiate-service-function-chain
| +--ro input
| | +--ro name string
| +--ro output
| +--ro name? string
+---x put-service-function-chains
+--ro input
+--ro service-function-chain* [name]
+--ro name string
+--ro symmetric? boolean
+--ro sfc-service-function* [name]
+--ro name string
+--ro type string
5.2. Service Function Chain Configuration Model
file "service-function-chain@2014-07-01.yang"
module service-function-chain {
namespace "urn:cisco:params:xml:ns:yang:sfc-sfc";
prefix sfc-sfc;
import ietf-inet-types { prefix inet; }
import ietf-yang-types { prefix yang; }
import service-function {prefix sfc-sf; }
organization "Cisco Systems, Inc.";
contact "Reinaldo Penno ";
Penno & Quinn Expires April 26, 2015 [Page 12]
Internet-Draft Yang Model for Service Chaining October 2014
description
"This module contains a collection of YANG definitions for
managing service function chains.
Copyright (c) 2013 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-07-01 {
description
"Revised based on Opendaylight Project feedback";
}
grouping service-function-chain-grouping {
list service-function-chain {
description
"A list that holds all service function chains in the
domain";
key "name";
leaf name {
type string;
description
"the name of the service function chain";
}
leaf symmetric {
type boolean;
description
"If the chain is symmetric we will create two service
paths, one ingress and another egress. Packets traverse
the egress service path in the reverse order of the
ingress path";
}
list sfc-service-function {
Penno & Quinn Expires April 26, 2015 [Page 13]
Internet-Draft Yang Model for Service Chaining October 2014
key "name";
leaf name {
type string;
description
"A unique handle that describes the service function
that will be chosen for this type, such as
ingress-dpi. This is not the service function name";
}
leaf type {
type string;
mandatory true;
description
"Service Function Type from service-function-type.yang";
}
ordered-by user;
description
"A list of service functions that compose the service
chain";
}
}
description
"This group bundles together all service function chains in the
domain";
}
// Service Function Chains
container service-function-chains {
uses service-function-chain-grouping;
description
"A service Function chain defines an
abstract set of service functions and their 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 nodes that copy to more than one branch, and also allows
for cases where there is flexibility in the order in which
services need to be applied. The term service chain is often
used as shorthand for service function chain.";
}
container service-function-chains-state {
config false;
list service-function-chain-state {
description
"A list that contains operational service function
chain state";
key "name";
Penno & Quinn Expires April 26, 2015 [Page 14]
Internet-Draft Yang Model for Service Chaining October 2014
leaf name {
type string;
description
"the name of the service function chain";
}
leaf-list sfc-service-function-path {
type string;
description
"A list of all service function paths instantiated from
this chain";
}
}
description
"This containers holds operational service function
chain state and their associated service path";
}
// Remote procedure calls
// (main feature: instantiation of a SFC)
rpc instantiate-service-function-chain {
description
"Instantiates a single service function";
input {
leaf name {
type string;
mandatory true;
description
"The name of the service function chain to be
instantiated.";
}
}
output {
leaf name {
type string;
description
"The name of the created service function path.";
}
}
}
// (RPC for testing)
rpc put-service-function-chains {
description
"Creates Service-Functions";
input {
uses service-function-chain-grouping;
Penno & Quinn Expires April 26, 2015 [Page 15]
Internet-Draft Yang Model for Service Chaining October 2014
}
}
}
6. Service Node (SN)
A Service Node is a virtual or physical element that houses one or
more service functions. A Service node might contain an entire
service function chain or be part of a larger service function chain.
6.1. Module Structure
module: service-node
+--rw service-nodes
+--rw service-node* [name]
+--rw name string
+--rw ip-mgmt-address? inet:ip-address
+--rw service-function* sfc-sf:service-function-ref
rpcs:
+---x put-service-node
+--ro input
+--ro name? string
+--ro ip-mgmt-address? inet:ip-address
+--ro service-function* sfc-sf:service-function-ref
6.2. Service Node Configuration Model
file "service-node@2014-07-01.yang"
module service-node {
namespace "urn:cisco:params:xml:ns:yang:sfc-sn";
prefix sfc-sn;
import ietf-inet-types { prefix inet; }
import ietf-yang-types { prefix yang; }
import service-function {prefix sfc-sf; }
Penno & Quinn Expires April 26, 2015 [Page 16]
Internet-Draft Yang Model for Service Chaining October 2014
organization "Cisco Systems, Inc.";
contact "Reinaldo Penno ";
description
"This module contains a collection of YANG definitions for
managing service function chains.
Copyright (c) 2013 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-07-01 {
description
"Revision based on Opendaylight project feedback";
}
// Service Nodes
typedef service-node-ref {
type leafref {
path "/sfc-sn:service-nodes/sfc-sn:service-node/sfc-sn:name";
}
description
"This type is used by data models that need to reference
configured service functions.";
}
grouping service-node-grouping {
leaf name {
Penno & Quinn Expires April 26, 2015 [Page 17]
Internet-Draft Yang Model for Service Chaining October 2014
type string;
description
"The name of the service node.";
}
leaf ip-mgmt-address {
type inet:ip-address;
}
leaf-list service-function {
type sfc-sf:service-function-ref;
description
"A list of service functions resident in this service node";
}
}
container service-nodes {
description
"Physical or virtual element that hosts one or
more service functions and has one or more network locators
associated with it for reachability and service delivery.";
list service-node {
key "name";
uses service-node-grouping;
}
}
// Remote procedure calls (for testing)
rpc put-service-node {
input {
uses service-node-grouping;
}
}
}
7. Service Function Path (SFP)
A Service Function Path is an instantiation of a service function
chain. It specifies the actual service functions (e.g. firewall1)
and the transport encapsulation used in the overlay.
Penno & Quinn Expires April 26, 2015 [Page 18]
Internet-Draft Yang Model for Service Chaining October 2014
7.1. Module Structure
module: service-function-path
+--rw service-function-paths
+--rw service-function-path* [name]
+--rw name string
+--rw context-metadata? string
+--rw variable-metadata? string
+--rw service-path-hop* [hop-number]
| +--rw hop-number uint8
| +--rw service-function-name? string
| +--rw service-function-forwarder? string
| +--rw service_index? uint8
+--rw service-chain-name string
+--rw starting-index? uint8
+--rw path-id? uint32 uint32
7.2. Service Function Path Configuration Model
file "service-function-path@2014-07-01.yang"
module service-function-path {
namespace "urn:cisco:params:xml:ns:yang:sfc-sfp";
prefix sfc-sfp;
import ietf-inet-types { prefix inet; }
import ietf-yang-types { prefix yang; }
import service-function {prefix sfc-sf; }
organization "Cisco Systems, Inc.";
contact "Reinaldo Penno ";
description
"This module contains a collection of YANG definitions for
managing service function chains.
Copyright (c) 2013 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
Penno & Quinn Expires April 26, 2015 [Page 19]
Internet-Draft Yang Model for Service Chaining October 2014
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-07-01 {
description
"Changes based on Opendaylight Testing and IETF SFC ml.";
}
typedef service-function-path-ref {
type leafref {
path "/sfc-sfp:service-function-paths/sfc-sfp:service-function-path/sfc-sfp:name";
}
description
"This type is used by data models that need to reference
configured service functions.";
}
// Service Function Path
container service-function-paths {
description
"The SFP provides a level of indirection
between the fully abstract notion of service chain as an
abstract sequence of functions to be delivered, and the
fully specified notion of exactly what SFF/SFs the packet
will visit when it actually traverses the network. By
allowing the control components to specify the use of this
level of indirection, the deployment may choose the degree
of SFF/SF selection authority that is delegated to the
network";
list service-function-path {
description
"A list that holds configuration data for all SFPs in the
domain";
key "name";
leaf name {
type string;
description
"The name of this service function path";
}
Penno & Quinn Expires April 26, 2015 [Page 20]
Internet-Draft Yang Model for Service Chaining October 2014
leaf context-metadata {
type string;
description
"The name of the associated context metadata";
}
leaf variable-metadata {
type string;
description
"The name of the associated variable metadata";
}
list service-path-hop {
key "hop-number";
leaf hop-number {
type uint8;
description
"A Monotonically increasing number";
}
leaf service-function-name {
type string;
description
"Service Function name";
}
leaf service-function-forwarder {
type string;
description
"Service Function Forwarder name";
}
leaf service_index {
type uint8;
description
"Provides location within the service path.
Service index MUST be decremented by service functions
or proxy nodes after performing required services. MAY
be used in conjunction with service path for path
selection. Service Index is also valuable when
troubleshooting/reporting service paths. In addition to
location within a path, SI can be used for loop
detection.";
}
ordered-by user;
description
"A list of service functions that compose the
service path";
}
leaf service-chain-name {
type string;
mandatory true;
description
Penno & Quinn Expires April 26, 2015 [Page 21]
Internet-Draft Yang Model for Service Chaining October 2014
"The Service Function Chain used as blueprint for this
path";
}
leaf starting-index {
type uint8;
description
"Starting service index";
}
leaf path-id {
type uint32 {
range "0..16777216";
}
description
"Identifies a service path.
Participating nodes MUST use this identifier for path
selection. An administrator can use the service path
value for reporting and troubleshooting packets along
a specific path.";
}
}
}
}
8. Service Function Forwarder (SFF)
This module describes the configuration a SFF needs to have in order
to route packets to the service functions it serves. the SFF needs to
have a table with service function name and associated locator. The
locator could be an IP address and port, an internal function call or
some other unique identifier.
8.1. Module Struture
Penno & Quinn Expires April 26, 2015 [Page 22]
Internet-Draft Yang Model for Service Chaining October 2014
module: service-function-forwarder
+--rw service-function-forwarders
+--rw service-function-forwarder* [name]
+--rw name string
+--rw service-node? string
+--rw classifier? string
+--rw sff-data-plane-locator* [name]
| +--rw name string
| +--rw data-plane-locator
| +--rw (locator-type)
| | +--:(ip)
| | | +--rw ip? inet:ip-address
| | | +--rw port? inet:port-number
| | +--:(lisp)
| | | +--rw eid? inet:ip-address
| | +--:(mac)
| | +--rw mac? yang:mac-address
| | +--rw vlan-id? uint16
| +--rw transport? identityref
+--rw service-function-dictionary* [name]
+--rw name string
+--rw type? string
+--rw sff-sf-data-plane-locator
| +--rw (locator-type)
| | +--:(ip)
| | | +--rw ip? inet:ip-address
| | | +--rw port? inet:port-number
| | +--:(lisp)
| | | +--rw eid? inet:ip-address
| | +--:(mac)
| | +--rw mac? yang:mac-address
| | +--rw vlan-id? uint16
| +--rw transport? identityref
+--rw sff-interfaces* [sff-interface]
| +--rw sff-interface string
+--rw failmode? failmode-type
8.2. Service Function Forwarder Model
file "service-function-forwarder@2014-07-01.yang"
module service-function-forwarder {
namespace "urn:cisco:params:xml:ns:yang:sfc-sff";
prefix sfc-sff;
Penno & Quinn Expires April 26, 2015 [Page 23]
Internet-Draft Yang Model for Service Chaining October 2014
import ietf-inet-types { prefix inet;}
import ietf-yang-types {
prefix "yang";
revision-date 2013-07-15;
}
import service-locator { prefix sfc-sl; }
organization "Cisco Systems, Inc.";
contact "Reinaldo Penno ";
description
"This module contains a collection of YANG definitions for
managing service function forwarders.
Copyright (c) 2013 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-07-01 {
description
"Revision based on Opendaylight project feedback";
}
// Failmode type definitions
identity failmode-type-identity {
description
"Base identity from which specific failmode
types are derived. Fail mode specifies the behavior
when the interface does not have connectivity to the
service node.";
}
Penno & Quinn Expires April 26, 2015 [Page 24]
Internet-Draft Yang Model for Service Chaining October 2014
typedef failmode-type {
type identityref {
base "failmode-type-identity";
}
description "This type is used to reference all
registered failmode types";
}
identity close {
base "failmode-type-identity";
description "When service-function can not reach service
function, packets will be dropped";
}
identity open {
base "failmode-type-identity";
description "When service-function can not reach service
function, packets will be forwarded";
}
container service-function-forwarders {
description
"A service function forwarder is
responsible for delivering traffic received from the SFC
network forwarder to one or more connected service
functions via information carried in the SFC encapsulation.
";
list service-function-forwarder {
description
"A list that holds configuration of all SFFs in the domain";
key "name";
leaf name {
type string;
description
"The unique name of this service function forwarder, such
as ovs-1-bridge-2.";
}
leaf service-node {
type string;
description "The service node that hosts this SFF";
}
leaf classifier {
type string;
description "the access-list responsible for directing
packets to a specific service path";
Penno & Quinn Expires April 26, 2015 [Page 25]
Internet-Draft Yang Model for Service Chaining October 2014
}
list sff-data-plane-locator {
description
"A list of all data-plane-locators of this SFF.";
key "name";
leaf name {
type string;
description
"A unique string that represents this
data-plane-locator";
}
container data-plane-locator {
description
"A network data-plane locator";
uses sfc-sl:data-plane-locator;
}
}
list service-function-dictionary {
key "name";
leaf name {
type string;
description
"The name of the service function.";
}
leaf type {
type string;
description
"Service Function Type from service-function-type yang
model";
}
container sff-sf-data-plane-locator {
description
"A network data-plane locator";
uses sfc-sl:data-plane-locator;
}
list sff-interfaces {
key "sff-interface";
leaf sff-interface {
type string;
description
"An individual interface on the SFF connected to the
SF";
}
description
"A list of interfaces on the SFF which are connected
Penno & Quinn Expires April 26, 2015 [Page 26]
Internet-Draft Yang Model for Service Chaining October 2014
to this SF, will usually be 1 or 2 elements";
}
leaf failmode {
type failmode-type;
description
"This leaf defines what should the SFF do if it can not
send packets to the SF";
}
description
"A list of all Service Functions attached to this SFF.";
}
}
}
}
9. Service Function Forwarder Open vSwitch (SFF-OVS)
This module augments the SFF model for Open vSwitch, meaning when
Open vSwitche (OVS) bridges are used as SFF.
9.1. Module Struture
module: service-function-forwarder-ovs
augment /sfc-sff:service-function-forwarders/sfc-sff:service-function-forwarder:
+--rw ovs
+--rw uuid? yang:uuid
+--rw external-ids* [name]
| +--rw name string
| +--rw value? string
+--rw bridge-name? string
+--rw rest-uri? inet:uri
9.2. Service Function Forwarder OVS Model
file "service-function-forwarder-ovs@2014-07-01.yang"
module service-function-forwarder-ovs {
yang-version 1;
namespace "urn:cisco:params:xml:ns:yang:sfc-sff-ovs";
Penno & Quinn Expires April 26, 2015 [Page 27]
Internet-Draft Yang Model for Service Chaining October 2014
prefix sfc-sff-ovs;
import service-function-forwarder {
prefix "sfc-sff";
}
import ietf-inet-types {
prefix "inet";
}
import ietf-yang-types {
prefix "yang";
revision-date 2013-07-15;
}
organization "Cisco Systems, Inc.";
contact "Reinaldo Penno ";
revision 2014-07-01 {
description "Augmentation of SFF for OVS";
}
augment "/sfc-sff:service-function-forwarders/"
+ "sfc-sff:service-function-forwarder" {
container ovs {
leaf uuid {
description "OVSDB bridge UUID";
type yang:uuid;
}
list external-ids {
description
"The list of external ids associated with this
bridge";
key "name";
leaf name {
type string;
description
"A unique string that represents this external-id such
as attached-mac";
}
leaf value {
type string;
description
"A unique string that represents the value of the
external-id such as fa:16:3e:56:47:10";
}
}
Penno & Quinn Expires April 26, 2015 [Page 28]
Internet-Draft Yang Model for Service Chaining October 2014
leaf bridge-name {
description "OVSDB bridge name";
type string;
}
leaf rest-uri {
description "URI of REST based management";
type inet:uri;
}
}
}
}
10. Service Locator (SL)
This module provides a single point of registration for all network
locators types used in Services Function Chaining. the model can be
augmented at will with locators appropriate for each use-case.
10.1. Module Structure
10.2. Service Locator Module
file "service-locator@2014-07-01.yang"
module service-locator {
namespace "urn:cisco:params:xml:ns:yang:sfc-sl";
prefix sfc-sl;
import ietf-inet-types { prefix inet; }
import ietf-yang-types { prefix yang; }
organization "Cisco Systems, Inc.";
contact "Reinaldo Penno ";
description
"This module contains a collection of YANG definitions for
managing service locators. Service locators are used as
data plane network destinations for Service Functions and
Service Function Forwarders
It follows closely the constructs of
Penno & Quinn Expires April 26, 2015 [Page 29]
Internet-Draft Yang Model for Service Chaining October 2014
http://tools.ietf.org/html/draft-ietf-netmod-interfaces-cfg-12
Copyright (c) 2013 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
revision 2014-07-01 {
description
"Changes based on Opendaylight Testing.";
}
// Locator definitions
// Transport type definitions
identity transport-type {
description
"Base identity from which specific transport types are
derived.";
}
identity vxlan-gpe {
base "sl-transport-type";
description "Programmable vxlan transport type";
}
identity gre {
base "sl-transport-type";
description "GRE transport type";
}
identity other {
base "sl-transport-type";
description "unspecified transport type";
Penno & Quinn Expires April 26, 2015 [Page 30]
Internet-Draft Yang Model for Service Chaining October 2014
}
identity sl-transport-type {
base "transport-type";
description
"This identity is used as a base for all transport
types";
}
grouping lisp-locator {
description
"Data plane-locator: Lisp Eid(IP)";
leaf eid {
type inet:ip-address;
description "Data-plane IP address";
}
}
grouping ip-port-locator {
description
"Data plane-locator: IP address and L4 port";
leaf ip {
type inet:ip-address;
description "Data-plane IP address";
}
leaf port {
type inet:port-number;
description "Data-plane port number";
}
}
grouping mac-address-locator {
description
"Data plane-locator: mac address and optional vlan-id";
leaf mac {
type yang:mac-address;
description "Data-plane MAC address";
}
leaf vlan-id {
type uint16 {
range "1..4094";
}
description "Data-plane VLAN ID address";
}
}
grouping data-plane-locator {
Penno & Quinn Expires April 26, 2015 [Page 31]
Internet-Draft Yang Model for Service Chaining October 2014
description
"This group presents data-plane locator
information for service function elements in the domain";
choice locator-type {
mandatory true;
case ip {
uses ip-port-locator;
}
case lisp {
uses lisp-locator;
}
case mac {
uses mac-address-locator;
}
description "The collection of all possible data-plane
locators. Only one can be chosen";
}
leaf transport {
type identityref {
base sfc-sl:sl-transport-type;
}
}
}
}
11. IANA Considerations
TBD
12. Security Considerations
13. Acknowledgements
Thanks to Jan Medved, Ron Parker, Jan Lindblad, David Goldberg, Vina
Ermagan, Sam Hague and Vinayak Joshi and for reviews and suggestions.
14. Changes
-08
o Removed VXLAN-GPE model
o Added Service Function Forwarder OVS model
Penno & Quinn Expires April 26, 2015 [Page 32]
Internet-Draft Yang Model for Service Chaining October 2014
o Added metadata reference to Service Function Path
-07
o All models that need data plane locators reference service locator
model
o Service Locator module has locators for IP:port, VLAN:MAC, LISP
o A SF can have multiple data place locators
o SF and SFF are decoupled and have their own views of the network
o Service Function Chains and derived path can be symmtric (bi-dir)
or not
o Service Function Types separated into a model
o Service Function Path is a collection of service hops. This
allows hops such as SFF + classifier.
-06
o Introduced operational tree in some models based on testing and
user feedback.
o Introduced RPCs in some models
o Service Function Path needs SFC from which it will be instantiated
o Updated all module structures
o Introduced Service Locator module
-05
Changes based on Opendaylight Implementation Testing and Sfc-dev
mailing list feedback
o Service Node becomes a container for Service Functions. Moved
data plane items to SFF.
o Fixed Service Function Forwarders into a list so we cna have
multiple in a system
o Fixed Service Function Chain so it becomes a list of lists.
o Created RPCs for Service Functions and Service Chain
Penno & Quinn Expires April 26, 2015 [Page 33]
Internet-Draft Yang Model for Service Chaining October 2014
-04
o Fixed list inside Service Function Chain to read service-function-
type
o Small comment fixes
-03
o Revision dates consistent
o Service function chain to container + list in order to allow
multiple
o Service Function Path to cotainer + list
o VXLAN-gpe vni to multiple 8-bit fields
o Consistent typeref use
o Other consistency fixes
-02
o After Opendaylight Testing converted multiple leafs to lists
throughout all models
o Removed transport dependency. Transport could be layer-2, layer-
3, etc
o Used pathrefs similar to ietf-interfaces to reference
configuration names
o Other consistency fixes
15. References
15.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
Penno & Quinn Expires April 26, 2015 [Page 34]
Internet-Draft Yang Model for Service Chaining October 2014
15.2. Informative References
[I-D.ietf-sfc-problem-statement]
Quinn, P. and T. Nadeau, "Service Function Chaining
Problem Statement", draft-ietf-sfc-problem-statement-10
(work in progress), August 2014.
[I-D.quinn-sfc-arch]
Quinn, P. and J. Halpern, "Service Function Chaining (SFC)
Architecture", draft-quinn-sfc-arch-05 (work in progress),
May 2014.
[I-D.quinn-sfc-nsh]
Quinn, P., Guichard, J., Fernando, R., Surendra, S.,
Smith, M., Yadav, N., Agarwal, P., Manur, R., Chauhan, A.,
Elzur, U., Garg, P., McConnell, B., and C. Wright,
"Network Service Header", draft-quinn-sfc-nsh-03 (work in
progress), July 2014.
[I-D.quinn-vxlan-gpe]
Quinn, P., Agarwal, P., Fernando, R., Lewis, D., Kreeger,
L., Smith, M., Yadav, N., Yong, L., Xu, X., Elzur, U., and
P. Garg, "Generic Protocol Extension for VXLAN", draft-
quinn-vxlan-gpe-03 (work in progress), July 2014.
Authors' Addresses
Reinaldo Penno
Cisco Systems
170 West Tasman Dr
San Jose CA
USA
Email: repenno@cisco.com
Paul Quinn
Cisco Systems
170 West Tasman Dr
San Jose CA
USA
Email: paulq@cisco.com
Penno & Quinn Expires April 26, 2015 [Page 35]