TOC 
Internet Engineering Task ForceE. Haleplidis
Internet-DraftUniversity of Patras
Intended status: InformationalK. Ogawa
Expires: December 29, 2010NTT Corporation
 W. Wang
 Zhejiang Gongshang University
 J. Hadi Salim
 Mojatatu Networks
 June 27, 2010


Implementation Report for ForCES
draft-ietf-forces-implementation-report-02

Abstract

Forwarding and Control Element Separation (ForCES) defines an architectural framework and associated protocols to standardize information exchange between the control plane and the forwarding plane in a ForCES Network Element (ForCES NE). RFC3654 has defined the ForCES requirements, and RFC3746 has defined the ForCES framework.

This document is an implementation report of the ForCES Protocol, Model and SCTP-TML, including the report on interoperability testing and the current state of ForCES implementations.

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 December 29, 2010.

Copyright Notice

Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.



Table of Contents

1.  Terminology and Conventions
    1.1.  Requirements Language
    1.2.  Definitions
2.  Introduction
    2.1.  ForCES Protocol
    2.2.  ForCES Model
    2.3.  Transport mapping layer
3.  Summary
4.  Methodology
5.  Exceptions
6.  Detail Section
    6.1.  Implementation Experience
        6.1.1.  ForCES Protocol Features
            6.1.1.1.  Protocol Messages
            6.1.1.2.  MainHeader Handling
            6.1.1.3.  TLV Handling
            6.1.1.4.  Operation Types Supported
            6.1.1.5.  ForCES Protocol Advanced Features
        6.1.2.  ForCES Model Features
            6.1.2.1.  Basic Atomic Types Supported
            6.1.2.2.  Compound Types Supported
            6.1.2.3.  LFBs Supported
        6.1.3.  ForCES SCTP-TML Features
            6.1.3.1.  TML Priority Ports
            6.1.3.2.  Message Handling at specific priorities
            6.1.3.3.  TML Security Feature
    6.2.  Interoperability Report
        6.2.1.  Scenarios
            6.2.1.1.  Scenario 1 - Pre-association Setup
            6.2.1.2.  Scenario 2 - TML priority channels connection
            6.2.1.3.  Scenario 3 - Association Setup - Association Complete
            6.2.1.4.  Scenario 4 - CE query
            6.2.1.5.  Scenario 5 - Heartbeat monitoring
            6.2.1.6.  Scenario 6 - Simple Config Command
            6.2.1.7.  Scenario 7 - Association Teardown
        6.2.2.  Tested Features
            6.2.2.1.  ForCES Protocol Features
            6.2.2.2.  ForCES Model Features
            6.2.2.3.  ForCES SCTP-TML Features
        6.2.3.  Interoperability Results
7.  Acknowledgements
8.  IANA Considerations
9.  Security Considerations
10.  References
    10.1.  Normative References
    10.2.  Informative References
§  Authors' Addresses




 TOC 

1.  Terminology and Conventions



 TOC 

1.1.  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 [RFC2119] (Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.).



 TOC 

1.2.  Definitions

This document follows the terminology defined by the ForCES Requirements in [RFC3654] (Khosravi, H. and T. Anderson, “Requirements for Separation of IP Control and Forwarding,” November 2003.) and by the ForCES framework in [RFC3746] (Yang, L., Dantu, R., Anderson, T., and R. Gopal, “Forwarding and Control Element Separation (ForCES) Framework,” April 2004.). The definitions below are repeated below for clarity.

Control Element (CE) - A logical entity that implements the ForCES protocol and uses it to instruct one or more FEs on how to process packets. CEs handle functionality such as the execution of control and signaling protocols.
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 one or more CEs via the ForCES protocol.
LFB (Logical Function Block) - The basic building block that is operated on by the ForCES protocol. The LFB is a well defined, logically separable functional block that resides in an FE and is controlled by the CE via ForCES protocol. The LFB may reside at the FE's datapath and process packets or may be purely an FE control or configuration entity that is operated on by the CE. Note that the LFB is a functionally accurate abstraction of the FE's processing capabilities, but not a hardware-accurate representation of the FE implementation.
LFB Class and LFB Instance - LFBs are categorized by LFB Classes. An LFB Instance represents an LFB Class (or Type) existence. There may be multiple instances of the same LFB Class (or Type) in an FE. An LFB Class is represented by an LFB Class ID, and an LFB Instance is represented by an LFB Instance ID. As a result, an LFB Class ID associated with an LFB Instance ID uniquely specifies an LFB existence.
LFB Metadata - Metadata is used to communicate per-packet state from one LFB to another, but is not sent across the network. The FE model defines how such metadata is identified, produced and consumed by the LFBs. It defines the functionality but not how metadata is encoded within an implementation.
LFB Components - Operational parameters of the LFBs that must be visible to the CEs are conceptualized in the FE model as the LFB components. The LFB components include, for example, flags, single parameter arguments, complex arguments, and tables that the CE can read and/or Components write via the ForCES protocol (see below).
ForCES Protocol - While there may be multiple protocols used within the overall ForCES architecture, the term "ForCES protocol" and "protocol" refer to the Fp reference points in the ForCES Framework in [RFC3746]. This protocol does not apply to CE-to-CE communication, FE-to-FE communication, or to communication between FE and CE managers. Basically, the ForCES protocol works in a master- slave mode in which FEs are slaves and CEs are masters. This document defines the specifications for this ForCES protocol.
ForCES Protocol Transport Mapping Layer (ForCES TML) - A layer in ForCES protocol architecture that uses the capabilities of existing transport protocols to specifically address protocol message transportation issues, such as how the protocol messages are mapped to different transport media (like TCP, IP, ATM, Ethernet, etc), and how to achieve and implement reliability, multicast, ordering, etc. The ForCES TML specifications are detailed in separate ForCES documents, one for each TML.


 TOC 

2.  Introduction

This is an implementation report for the ForCES protocol, model and SCTP-TML documents and includes an interoperability report.

It follows the outline suggested by [RFC5657] (Dusseault, L. and R. Sparks, “Guidance on Interoperation and Implementation Reports for Advancement to Draft Standard,” September 2009.).

Forwarding and Control Element Separation (ForCES) defines an architectural framework and associated protocols to standardize information exchange between the control plane and the forwarding plane in a ForCES Network Element (ForCES NE). [RFC3654] (Khosravi, H. and T. Anderson, “Requirements for Separation of IP Control and Forwarding,” November 2003.) has defined the ForCES requirements, and [RFC3746] (Yang, L., Dantu, R., Anderson, T., and R. Gopal, “Forwarding and Control Element Separation (ForCES) Framework,” April 2004.) has defined the ForCES framework.



 TOC 

2.1.  ForCES Protocol

The ForCES protocol works in a master-slave mode in which FEs are slaves and CEs are masters. The protocol includes commands for transport of Logical Function Block (LFB) configuration information, association setup, status, and event notifications, etc. The reader is encouraged to read the ForCES Protocol (Doria, A., Hadi Salim, J., Haas, R., Khosravi, H., Wang, W., Dong, L., Gopal, R., and J. Halpern, “Forwarding and Control Element Separation (ForCES) Protocol Specification,” March 2010.) [RFC5810] for further information.



 TOC 

2.2.  ForCES Model

The ForCES Model (Halpern, J. and J. Hadi Salim, “Forwarding and Control Element Separation (ForCES) Forwarding Element Model,” March 2010.) [RFC5812] presents a formal way to define FE Logical Function Blocks (LFBs) using XML. LFB configuration components, capabilities, and associated events are defined when the LFB is formally created. The LFBs within the FE are accordingly controlled in a standardized way by the ForCES protocol.



 TOC 

2.3.  Transport mapping layer

The TML transports the PL messages. The TML is where the issues of how to achieve transport level reliability, congestion control, multicast, ordering, etc. are handled. All ForCES Protocol Layer implementations MUST be portable across all TMLs. Although more than one TML may be standardized for the ForCES Protocol, all implementations MUST implement the SCTP-TML (Hadi Salim, J. and K. Ogawa, “SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol,” March 2010.) [RFC5811].



 TOC 

3.  Summary

The authors attest that the ForCES Protocol, Model and SCTP-TML meet the requirements for Draft Standard.

Three independent implementations, NTT Japan, University of Patras and Zhejiang Gongshang University, were surveyed and found to already implement all the major features. All implementors mentioned they will be implementing all missing features in the future.

An interop test was conducted in July, 2009 for all three implementations. Two other organizations, Mojatatu Networks and Hangzhou Baud Information and Networks Technology Corporation, which independently extended two different well known public domain protocol analyzers, Ethereal/Wireshark and tcpdump, also participated in the interop for a total of five independent organizations implementing. The two protocol analyzers were used to verify validity of ForCEs protocol messages (and in some cases semantics).

There were no notable difficulties in the interoperability test and almost all issues were code bugs that were dealt with mostly on site and tests repeated successfully as stated in Section 6.2.3 (Interoperability Results).



 TOC 

4.  Methodology

This report has both an implementation experience survey as well as the results of the interoperability test.

The survey information was gathered after implementors answered a brief questionnaire with all ForCES Protocol, Model and SCTP-TML features. The results can be seen in Section 6.1 (Implementation Experience)

The interoperability results were part of the interoperability test. Extended Ethereal and extended Tcpdump were used to verify the results. The results can be seen in Section 6.2 (Interoperability Report)



 TOC 

5.  Exceptions

The core features of the ForCES Protocol, Model and SCTP-TML have been implemented and tested in an interop in July, 2009. The intention of the interop testing was to validate that all the main features of the 3 core documents were inter-operable amongst different implementations. The tested features can be seen in Section 6.2.2 (Tested Features).

Different organizations surveyed have implemented certain features but not others. This approach is driven by presence of different LFBs the different organizations have currently implemented. All organizations surveyed have indicated intention to implement all outstanding features in due time. The implemented features can be seen in Section 6.1 (Implementation Experience).

The mandated TML security requirement, IPSec, was not validated during the interop and is not discussed in this document. Since IPSec is well known and widely deployed not testing in presence of IPSec does not invalidate the tests done. Note that Section 6.1.3.3 (TML Security Feature) indicates that none of the implementations reporting included support for IPSec, but all indicated their intention to implement.

Although the SCTP priority ports have been changed since the interoperability test with the latest SCTP-TML draft, the change has no impact in the validity of the interoperability test.



 TOC 

6.  Detail Section



 TOC 

6.1.  Implementation Experience

Three different organizations have implemented the ForCES Protocol, Model and SCTP-TML and answered a questionnaire. These are:

Also, not actual implementations, but extensions on protocol analyzers capable of understanding ForCES protocol messages, also are considered part of an implementation as they can offer validation of exchanged protocol messages. Two such extensions have been created:

All implementors were asked regarding the ForCES features they have implemented. For every item listed the respondents indicated whether they had implemented, will implement, or won't implement at all.



 TOC 

6.1.1.  ForCES Protocol Features



 TOC 

6.1.1.1.  Protocol Messages



Protocol MessageNTT JapanUniversity of PatrasZhejiang Gongshang University
Association Setup Implemented Implemented Implemented
Association Setup Response Implemented Implemented Implemented
Association TearDown Implemented Implemented Implemented
Configuration Implemented Implemented Implemented
Configuration Response Implemented Implemented Implemented
Query Implemented Implemented Implemented
Query Response Implemented Implemented Implemented
Event Notification Implemented Will Implement Implemented
Packet Redirect Implemented Will Implement Implemented
HeartBeat Implemented Implemented Implemented

 ForCES Protocol Message 



 TOC 

6.1.1.2.  MainHeader Handling



Header FieldNTT JapanUniversity of PatrasZhejiang Gongshang University
Correlator Implemented Implemented Implemented
Acknowledge Flag Implemented Implemented Implemented
Priority Flag Will Implement Implemented Implemented
Execution Mode Flag Will Implement Will Implement Implemented
Atomic Flag Will Implement Will Implement Implemented
Transaction Flag Will Implement Will Implement Implemented

 MainHeader Handling 



 TOC 

6.1.1.3.  TLV Handling



TLVNTT JapanUniversity of PatrasZhejiang Gongshang University
Redirect TLV Implemented Will Implement Implemented
Association Setup Result TLV Implemented Implemented Implemented
Association TearDown Reason TLV Implemented Implemented Implemented
LFBSelector TLV Implemented Implemented Implemented
Operation TLV Implemented Implemented Implemented
PathData TLV Implemented Implemented Implemented
KeyInfo TLV Will Implement Will Implement Implemented
FullData TLV Implemented Implemented Implemented
SparseData TLV Will Implement Will Implement Implemented
ILV Will Implement Will Implement Implemented
Metadata TLV Will Implement Will Implement Implemented
Result TLV Implemented Implemented Implemented
Redirect Data TLV Implemented Will Implement Implemented

 TLVs Supported 



 TOC 

6.1.1.4.  Operation Types Supported



OperationNTT JapanUniversity of PatrasZhejiang Gongshang University
Set Implemented Implemented Implemented
Set Prop Will Implement Will Implement Implemented
Set Response Implemented Implemented Implemented
Set Prop Response Will Implement Will Implement Implemented
Del Implemented Will Implement Implemented
Del Response Implemented Will Implement Implemented
Get Implemented Implemented Implemented
Get Prop Will Implement Will Implement Implemented
Get Response Implemented Implemented Implemented
Get Prop Response Will Implement Will Implement Implemented
Report Implemented Implemented Implemented
Commit Will Implement Will Implement Implemented
Commit Response Will Implement Will Implement Implemented
TRComp Will Implement Will Implement Implemented

 Operation Type Supported 



 TOC 

6.1.1.5.  ForCES Protocol Advanced Features



FeatureNTT JapanUniversity of PatrasZhejiang Gongshang University
Execute Mode Will Implement Will Implement Implemented
Transaction Will Implement Will Implement Implemented
Batching Will Implement Implemented Implemented
Command Pipelining Will Implement Will Implement Will Implement
HeartBeats Implemented Implemented Implemented

 ForCES Protocol Advanced Features 



 TOC 

6.1.2.  ForCES Model Features



 TOC 

6.1.2.1.  Basic Atomic Types Supported



Atomic TypeNTT JapanUniversity of PatrasZhejiang Gongshang University
char Implemented Implemented Will Implement
uchar Implemented Implemented Implemented
int16 Implemented Implemented Will Implement
uint16 Implemented Implemented Will Implement
int32 Implemented Implemented Implemented
uint32 Implemented Implemented Implemented
int16 Implemented Implemented Will Implement
uint64 Implemented Implemented Will Implement
boolean Implemented Implemented Implemented
string[N] Implemented Implemented Implemented
string Implemented Implemented Implemented
byte[N] Implemented Implemented Implemented
octetstring[N] Implemented Implemented Will Implement
float32 Implemented Implemented Will Implement
float64 Implemented Implemented Will Implement

 Basic Atomic Types Supported 



 TOC 

6.1.2.2.  Compound Types Supported



Compound TypeNTT JapanUniversity of PatrasZhejiang Gongshang University
structs Implemented Implemented Implemented
arrays Implemented Implemented Implemented

 Compound Types Supported 



 TOC 

6.1.2.3.  LFBs Supported



 TOC 

6.1.2.3.1.  FE Protocol LFB



Protocol DataTypesNTT JapanUniversity of PatrasZhejiang Gongshang University
CEHBPolicy Implemented Implemented Implemented
FEHIBPolicy Implemented Implemented Implemented
FERestarPolicy Implemented Implemented Implemented
CEFailoverPolicy Implemented Implemented Implemented
FEHACapab Implemented Implemented Will Implement

 FE Protocol LFB Datatypes 



Protocol ComponentsNTT JapanUniversity of PatrasZhejiang Gongshang University
CurrentRunningVersion Implemented Implemented Implemented
FEID Implemented Implemented Implemented
MulticastFEIDs Implemented Implemented Implemented
CEHBPolicy Implemented Implemented Implemented
CEHDI Implemented Implemented Implemented
FEHBPolicy Implemented Implemented Implemented
FEHI Implemented Implemented Implemented
CEID Implemented Implemented Implemented
BackupCEs Implemented Will Implement Will Implement
CEFailoverPolicy Implemented Implemented Implemented
CEFTI Implemented Implemented Implemented
FERestartPolicy Implemented Implemented Will Implement
LastCEID Implemented Implemented Will Implement

 FE Protocol LFB Components 



CapabilitiesNTT JapanUniversity of PatrasZhejiang Gongshang University
SupportableVersions Implemented Implemented Implemented
HACapabilities Implemented Implemented Will Implement

 Capabilities Supported 



EventsNTT JapanUniversity of PatrasZhejiang Gongshang University
PrimaryCEDown Will Implement Will Implement Will Implement

 Events Supported 



 TOC 

6.1.2.3.2.  FE Object LFB



Object DataTypesNTT JapanUniversity of PatrasZhejiang Gongshang University
LFBAdjacencyLimit Implemented Implemented Implemented
PortGroupLimitType Implemented Implemented Implemented
SupportedLFBType Implemented Implemented Implemented
FEStateValues Implemented Implemented Implemented
FEConfiguredeighborType Implemented Implemented Implemented
FEConfiguredeighborType Implemented Implemented Implemented
LFBSelectorType Implemented Implemented Implemented
LFBLinkType Implemented Implemented Implemented

 FE Object LFB Datatypes 



Object ComponentsNTT JapanUniversity of PatrasZhejiang Gongshang University
LFBTopology Implemented Implemented Implemented
LFBSelectors Implemented Implemented Implemented
FEName Implemented Implemented Implemented
FEID Implemented Implemented Implemented
FEVendor Implemented Implemented Implemented
FEModel Implemented Implemented Implemented
FEState Implemented Implemented Implemented
FENeighbors Implemented Implemented Implemented

 FE Object LFB Components 



CapabilitiesNTT JapanUniversity of PatrasZhejiang Gongshang University
ModifiableLFBTopology Implemented Implemented Implemented
SupportedLFBs Implemented Implemented Implemented

 Capabilities Supported 



 TOC 

6.1.3.  ForCES SCTP-TML Features



 TOC 

6.1.3.1.  TML Priority Ports



PortNTT JapanUniversity of PatrasZhejiang Gongshang University
High priority (6700) Implemented Implemented Implemented
Medium priority (6701) Implemented Implemented Implemented
Low priority (6702) Implemented Implemented Implemented

 Priority Ports 



 TOC 

6.1.3.2.  Message Handling at specific priorities



ForCES MessageNTT JapanUniversity of PatrasZhejiang Gongshang University
Association Setup Implemented Implemented Implemented
Association Setup Response Implemented Implemented Implemented
Association Teardown Implemented Implemented Implemented
Config Implemented Implemented Implemented
Config Response Implemented Implemented Implemented
Query Implemented Implemented Implemented
Query Response Implemented Implemented Implemented

 Message Handling at High priority (6700) Port 



ForCES MessageNTT JapanUniversity of PatrasZhejiang Gongshang University
Event Notification Implemented Implemented Implemented

 Message Handling at Medium priority (6701) Port 



ForCES MessageNTT JapanUniversity of PatrasZhejiang Gongshang University
Packet Redirect Implemented Implemented Implemented
Heartbeats Implemented Implemented Implemented

 Message Handling at Low priority (6702) Port 



 TOC 

6.1.3.3.  TML Security Feature



Security FeatureNTT JapanUniversity of PatrasZhejiang Gongshang University
IPSec Will Implement Will Implement Will Implement

 Security Feature Support 



 TOC 

6.2.  Interoperability Report

The interoperability test took place at the University of Patras, in the Department of Electrical and Computer Engineering.

There were two options to participate in the interoperability test.

1. Locally at the University of Patras premises.

2. Remotely via internet.

Implementations from NTT and University of Patras, were present locally at the University of Patras premises in Greece, while the implementation from Zhejiang Gongshang University, which was behind a NAT, connected remotely from China.

The interoperability test, tested the basic functionality of the ForCES protocol, mainly message exchanging and handling.

The following scenarios were tested.



 TOC 

6.2.1.  Scenarios

The main goal of the interoperability test was to test the basic protocol functionality, the test parameters were limited.

  1. In the Association Setup Message, all report messages were ignored.
  2. In the Association Setup Phase, the messages, FEO OperEnable Event (FE to CE), Config FEO Adminup (CE to FE) and FEO Config-Resp (FE to CE) were ignored. The CEs assumed that the FEs were enabled once the LFBSelectors had been queried.
  3. Only FullDataTLVs were used and not SparseData TLVs.
  4. There were no transaction operations.
  5. Each message had only one LFBSelector TLV, one Operation TLV and one PathDataTLV per message when these were used.


 TOC 

6.2.1.1.  Scenario 1 - Pre-association Setup

While the Pre-association setup is not in the ForCES current scope it is an essential step before CEs and FEs communicate. As the first part in a successful CE-FE connection the participating CEs and FEs had to be able to be configured.

In the Pre-association Phase the following configuration items were setup regarding the CEs:

In the Pre-association Phase the following configuration items were setup regarding the FEs:



 TOC 

6.2.1.2.  Scenario 2 - TML priority channels connection

For the interoperability test, the SCTP was used as TML. The TML connection with the associating element was needed for the scenario 2 to be successful.

Although SCTP-TML (Hadi Salim, J. and K. Ogawa, “SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol,” March 2010.) [RFC5811] defines 3 priority channels, with specific ports:

At the time of the interoperability test, the sctp ports of the three priority channels were the following:

As specified in the exceptions section, this does not invalidate the results of the interoperability test.



 TOC 

6.2.1.3.  Scenario 3 - Association Setup - Association Complete

Once the Pre-association phase had been complete in the previous 2 scenarios, CEs and FEs would be ready to communicate using the ForCES protocol, and enter the Association Setup stage. In this stage the FEs would attempt to join the NE. The following ForCES protocol messages would be exchanged for each CE-FE pair in the specified order:



 TOC 

6.2.1.4.  Scenario 4 - CE query

Once the Association Phase stage has been complete, the FEs and CEs would enter the Established stage. In this stage the FE will be continuously updated or queried. The CE should query the FE a specific value from the FE Object LFB and from the FE Protocol LFB. An example from the FE Protocol LFB is the HeartBeat Timer (FEHI) and from the FE Object LFB is the State of the LFB (FEState)

The following ForCES protocol messages were exchanged:



 TOC 

6.2.1.5.  Scenario 5 - Heartbeat monitoring

The Heartbeat (HB) Message is used for one ForCES element (FE or CE) to asynchronously notify one or more other ForCES elements in the same ForCES NE on its liveness. The default configuration of the Heartbeat Policy of the FE is set to 0 which means, that the FE should not generate any Heartbeat messages. the CE is responsible for checking FE liveness by setting the PL header ACK flag of the message it sends to AlwaysACK. In this Scenario the CE will send a Heartbeat message with the ACK flag set to AlwaysACK and the FE should respond.

The following ForCES protocol messages were exchanged:



 TOC 

6.2.1.6.  Scenario 6 - Simple Config Command

A config message is sent by the CE to the FE to configure LFB components in the FE. A simple config command easily visible and metered would be to change the Heartbeat configuration. This was done in two steps:

  1. Change the FE Heartbeat Policy (FEHBPolicy) to value 1, to force the FE to send heartbeats.
  2. After some heartbeats from the FE, the FE Heartbeat Interval (FEHI) was changed.

The following ForCES protocol messages were exchanged:



 TOC 

6.2.1.7.  Scenario 7 - Association Teardown

In the end, the association must be terminated. There were three scenarios by which the association was terminated:

  1. Normal tear down by exchanging Association Teardown Message
  2. Irregular tear down by stopping heartbeats from a FE or a CE.
  3. Irregular tear down by externally shutting down/rebooting a FE or a CE.

All scenarios were tested in the interoperability test.

The following ForCES protocol messages were exchanged:



 TOC 

6.2.2.  Tested Features

The features that were tested are:



 TOC 

6.2.2.1.  ForCES Protocol Features



 TOC 

6.2.2.1.1.  Protocol Messages



Protocol Message
Association Setup
Association Setup Response
Association TearDown
Configuration
Configuration Response
Query
Query Response
HeartBeat

 ForCES Protocol Message 



 TOC 

6.2.2.1.2.  MainHeader Handling



Header Field
Correlator
Acknowledge Flag
Priority Flag

 MainHeader Handling 



 TOC 

6.2.2.1.3.  TLV Handling



TLV
Association Setup Result TLV
Association TearDown Reason TLV
LFBSelector TLV
Operation TLV
PathData TLV
FullData TLV
Result TLV

 TLVs Supported 



 TOC 

6.2.2.1.4.  Operation Types Supported



Operation
Set
Set Response
Get
Get Response
Report

 Operation Type Supported 



 TOC 

6.2.2.1.5.  ForCES Protocol Advanced Features



Feature
Batching
HeartBeats

 ForCES Protocol Advanced Features 

Although Batching was not initially designed to be tested, it was tested during the interoperability test.



 TOC 

6.2.2.2.  ForCES Model Features



 TOC 

6.2.2.2.1.  Basic Atomic Types Supported



Atomic Type
uchar
uint32

 Basic Atomic Types Supported 



 TOC 

6.2.2.2.2.  Compound Types Supported



Compound Type
structs
arrays

 Compound Types Supported 



 TOC 

6.2.2.2.3.  LFBs Supported



 TOC 

6.2.2.2.3.1.  FE Protocol LFB



Protocol DataTypes
CEHBPolicy
FEHIBPolicy

 FE Protocol LFB Datatypes 



Protocol Components
FEID
CEHBPolicy
CEHDI
FEHBPolicy
FEHI
CEID

 FE Protocol LFB Components 



 TOC 

6.2.2.2.3.2.  FE Object LFB



Object DataTypes
FEStateValues
LFBSelectorType

 FE Object LFB Datatypes 



Object Components
LFBSelectors
FEState

 FE Object LFB Components 



 TOC 

6.2.2.3.  ForCES SCTP-TML Features



 TOC 

6.2.2.3.1.  TML Priority Ports



Port
High priority (6700)
Medium priority (6701)
Low priority (6702)

 Priority Ports 



 TOC 

6.2.2.3.2.  Message Handling at specific priorities



ForCES Message
Association Setup
Association Setup Response
Association Teardown
Config
Config Response
Query
Query Response

 Message Handling at High priority (6700) Port 



ForCES Message
Heartbeats

 Message Handling at Low priority (6702) Port 



 TOC 

6.2.3.  Interoperability Results

All implementations were found to be interoperable with each other.

All scenarios were tested successfully.

The following issues were found and dealt with.

  1. Some messages were sent on the wrong priority channels. There were some ambiguities on the SCTP-TML document on how to deal with such a situation. The possibilities were: an FE response on the same (wrong) channel as a CE query; on the correctly documented channel for the message; or to simply drop the packet. This has been corrected by mandating the message to channel mapping to be a MUST in the SCTP-TML document (Hadi Salim, J. and K. Ogawa, “SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol,” March 2010.) [RFC5811] before it was published as an RFC.
  2. At some point, a CE sent a TearDown message to the FE. The CE expected the FE to shut down the connection, and the FE waited the CE to shut down the connection and were caught in a deadlock. This was a code bug and was fixed.
  3. Sometimes, only when the CE and FE were remote to each other (one being in China and another in Greece), the association setup message was not received by the CE side and therefore an association never completed. This was not an implementation issue, rather it was a network issue. This issue is solved with the retransmission of the non delivered messages.
  4. An implementation did not take into account that the padding in TLVs MUST NOT be included in the length of the TLV. This was a code bug and was fixed.
  5. EM Flag was set to reserved by a CE and was not ignored by the FE. This was a code bug and was fixed.
  6. After the FEHBPolicy was set to 1 the FE didn't send any HeartBeats. This was a code bug and was fixed.
  7. Some FEs sent HeartBeats with the ACK flag with a value other than NoACK. The CE responded. This was a code bug and was fixed.
  8. When a cable was disconnected, all TML implementation didn't detect it. The association was eventually dropped due to heartbeats, this was a success, but this is an implementation issue implementers should keep in mind. This is a SCTP options issue. Nothing was needed to be done.
  9. A CE crashed due to unknown LFBSelector values. This was a code bug and was fixed.
  10. With the remote connection from China, which was behind a NAT, to Greece there were a lot of ForCES packet retransmission. The problem is that packets like Heartbeats were retransmitted. This was an implementation issue regarding SCTP usage implementers should keep in mind. SCTP-PR option was needed to be used. Nothing was needed to be done.

The interoperability test went so well that an additional extended test was added to test for batching messages. This test was also done successfully.



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7.  Acknowledgements

The authors like to give thanks to Professors Odysseas Koufopavlou and Spyros Denazis, and the Department of Electrical and Computer Engineering in the University of Patras who hosted the ForCES interoperability test.

Also the authors would like to give thanks to Chuanhuang Li, Ming Gao, and other participants from Zhejiang Gongshang University which connected remotely. This allowed the discovery of a series of issues that would have been uncaught otherwise.

The authors would like to thank also Hideaki Iwata and Yoshinobu Morimoto for participating locally at the interoperability test and also Hiroki Date and Hidefumi Otsuka all part of NTT Japan for contributing to the interoperability test.

Additionally thanks are given to Xinping Wang for her help in writing the interoperability draft and Fenggen Jia for extending the Ethereal protocol analyzer.



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8.  IANA Considerations

This memo includes no request to IANA.



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9.  Security Considerations

No security elements of the protocol or the SCTP TML (Hadi Salim, J. and K. Ogawa, “SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol,” March 2010.) [RFC5811] specification were tested.

The survey indicated that no security elements were implemented but all participants indicated their intention to implement

For security considerations regarding the ForCES Protocol and the SCTP-TML please see [RFC5810] (Doria, A., Hadi Salim, J., Haas, R., Khosravi, H., Wang, W., Dong, L., Gopal, R., and J. Halpern, “Forwarding and Control Element Separation (ForCES) Protocol Specification,” March 2010.) and [RFC5811] (Hadi Salim, J. and K. Ogawa, “SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol,” March 2010.)



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10.  References



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10.1. Normative References

[RFC5810] Doria, A., Hadi Salim, J., Haas, R., Khosravi, H., Wang, W., Dong, L., Gopal, R., and J. Halpern, “Forwarding and Control Element Separation (ForCES) Protocol Specification,” RFC 5810, March 2010 (TXT).
[RFC5811] Hadi Salim, J. and K. Ogawa, “SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol,” RFC 5811, March 2010 (TXT).
[RFC5812] Halpern, J. and J. Hadi Salim, “Forwarding and Control Element Separation (ForCES) Forwarding Element Model,” RFC 5812, March 2010 (TXT).


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10.2. Informative References

[RFC2119] Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” BCP 14, RFC 2119, March 1997 (TXT, HTML, XML).
[RFC3654] Khosravi, H. and T. Anderson, “Requirements for Separation of IP Control and Forwarding,” RFC 3654, November 2003 (TXT).
[RFC3746] Yang, L., Dantu, R., Anderson, T., and R. Gopal, “Forwarding and Control Element Separation (ForCES) Framework,” RFC 3746, April 2004 (TXT).
[RFC5657] Dusseault, L. and R. Sparks, “Guidance on Interoperation and Implementation Reports for Advancement to Draft Standard,” BCP 9, RFC 5657, September 2009 (TXT).
[ethereal] Ethereal is a protocol analyzer. The specific ethereal that was used is an updated Ethereal, by Fenggen Jia, that can analyze and decode the ForCES protocol messages..”
[tcpdump] Tcpdump is a linux protocol analyzer. The specific tcpdump that was used is a modified tcpdump, by Jamal Hadi Salim, that can analyze and decode the ForCES protocol messages..”


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Authors' Addresses

  Evangelos Haleplidis
  University of Patras
  Patras,
  Greece
Email:  ehalep@ece.upatras.gr
  
  Kentaro Ogawa
  NTT Corporation
  Tokyo,
  Japan
Email:  ogawa.kentaro@lab.ntt.co.jp
  
  Weiming Wang
  Zhejiang Gongshang University
  18, Xuezheng Str., Xiasha University Town
  Hangzhou, 310018
  P.R.China
Phone:  +86-571-28877721
Email:  wmwang@mail.zjgsu.edu.cn
  
  Jamal Hadi Salim
  Mojatatu Networks
  Ottawa, Ontario,
  Canada
Phone: 
Email:  hadi@mojatatu.com