Internet DRAFT - draft-dhody-pce-iro-survey
draft-dhody-pce-iro-survey
PCE Working Group D. Dhody
Internet-Draft Huawei Technologies
Intended status: Informational December 26, 2014
Expires: June 29, 2015
Informal Survey into Include Route Object (IRO) Implementations in Path
Computation Element communication Protocol (PCEP)
draft-dhody-pce-iro-survey-02
Abstract
During discussions of a document to provide a standard representation
and encoding of Domain-Sequence within the Path Computation Element
(PCE) communication Protocol (PCEP) for communications between a Path
Computation Client (PCC) and a PCE, or between two PCEs. It was
determined that there was a need for clarification with respect to
the ordered nature of the Include Route Object (IRO).
Since there was a proposal to have a new IRO type with ordering, as
well as handling of Loose bit (L-Bit), it felt necessary to conduct a
survey of the existing and planned implementations.
This document summarizes the survey questions and captures the
results. Some conclusions are also presented.
This survey was informal and conducted via email. Responses were
collected and anonymized by the PCE working group chairs.
Status of This Memo
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This Internet-Draft will expire on June 29, 2015.
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Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Survey Details . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Survey Preamble . . . . . . . . . . . . . . . . . . . . . 3
2.2. Survey Questions . . . . . . . . . . . . . . . . . . . . 3
3. Respondents . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1. Proposed Action . . . . . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 8
Appendix A. Contributor Addresses . . . . . . . . . . . . . . . 10
1. Introduction
The Path Computation Element Communication Protocol (PCEP) provides
mechanisms for Path Computation Elements (PCEs) to perform path
computations in response to Path Computation Clients (PCCs) requests.
[RFC5440] defines the Include Route Object (IRO) to specify that the
computed path must traverse a set of specified network elements. The
specification did not mention if IRO is an ordered or un-ordered list
of sub-objects. It mentioned that the L bit (loose) has no meaning
within an IRO.
[RFC5441] suggested the use of IRO to indicate the sequence of
domains to be traversed during inter-domain path computation.
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During discussion of [I-D.ietf-pce-pcep-domain-sequence] it was
proposed to have a new IRO type with ordered nature, as well as
handling of L bit.
In order to discover the current state of affairs amongst
implementations a survey of the existing and planned implementations
was conducted. This survey was informal and conducted via email.
Responses were collected and anonymized by the PCE working group
chair.
This document summarizes the survey questions and captures the
results. Some conclusions are also presented.
2. Survey Details
2.1. Survey Preamble
The survey was introduced with the following text.
Hi PCE WG.
To address the issues associated with draft-ietf-pce-pcep-domain-
sequence and "Include Route Object" in PCEP, Dhruv has proposed to
start a small survey. If implementers agree that we need to clarify
this, they would be much welcome to answer the attached questions.
Dhruv will process the results, but to improve confidentiality,
answers may be sent privately to the chairs.
Thanks,
JP & Julien, on behalf of Dhruv
2.2. Survey Questions
The following survey questions were asked, the survey questionnaire
is listed verbatim below.
During discussion of draft-ietf-pce-pcep-domain-sequence-05,
it has been noted that RFC 5440 does not define whether the
sub-objects in the IRO are ordered or unordered.
We would like to do an informal and *confidential* survey
of current implementations, to help clarify this
situation.
1. IRO Encoding
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a. Does your implementation construct IRO?
b. If your answer to part (a) is Yes, does your
implementation construct the IRO as an ordered list
always, sometimes or never?
c. If your answer to part (b) is Sometimes, what criteria
do you use to decide if the IRO is an ordered or
unordered list?
d. If your answer to part (b) is Always or Sometimes, does
your implementation construct the IRO as a sequence of
strict hops or as a sequence of loose hops?
2. IRO Decoding
a. Does your implementation decode IRO?
b. If your answer to part (a) is Yes, does your
implementation interpret the decoded IRO as an ordered
list always, sometimes or never?
c. If your answer to part (b) is Sometimes, what criteria do
you use to decide if the IRO is an ordered or unordered
list?
d. If your answer to part (b) is Always or Sometimes, does
your implementation interpret the IRO as a sequence of
strict hops or as a sequence of loose hops?
3. Impact
a. Will there be an impact to your implementation if RFC 5440
is updated to state that the IRO is an ordered list?
b. Will there be an impact to your implementation if RFC 5440
is updated to state that the IRO is an unordered list?
c. If RFC 5440 is updated to state that the IRO is an
ordered list, will there be an impact to your
implementation if RFC 5440 is also updated to allow IRO
sub-objects to use the loose bit (L-bit)?
4. Respondents
a. Are you a Vendor/Research Lab/Software House/Other (please
specify)?
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b. If your answer to part (a) is Vendor, is the
implementation for a shipping product, product under
development or a prototype?
3. Respondents
Total 9 responses were received from vendors, software houses, and
research labs. Vendors made responses for their current shipping
products as well as products that they currently have under
development.
o Total Number of Respondents: 9
* Vendors: 4
+ Shipping Product: 1
+ Product Under Development: 1
+ Prototype: 1
+ Unknown: 1
* Software House: 1
* Research Labs: 2
+ Operator's Research Facility: 1
* Open Source: 1
+ Shipped Release: 1
* Others (or Unknown): 1
4. Results
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+----+---------------------------------------------+----------------+
| | Questions | Response |
+----+---------------------------------------------+----------------+
| 1a | Does your implementation construct IRO? | yes (9) |
| | | |
| 1b | Does your implementation construct the IRO | always (8), |
| | as an ordered list always, sometimes or | never (1) |
| | never? | |
| | | |
| 1c | What criteria do you use to decide if the | none (9) |
| | IRO is an ordered or unordered list? | |
| | | |
| 1d | Does your implementation construct the IRO | strict (5), |
| | as a sequence of strict hops or as a | loose (2), |
| | sequence of loose hops? | both (2) |
+----+---------------------------------------------+----------------+
Table 1: IRO Encoding
Regarding IRO encodings, most implementations construct IRO in an
ordered fashion and consider it to be an ordered list. More than
half of implementation under survey consider the IRO sub-objects as
strict hops, others consider loose or support both.
+----+--------------------------------------------+-----------------+
| | Questions | Response |
+----+--------------------------------------------+-----------------+
| 2a | Does your implementation decode IRO? | yes (9) |
| | | |
| 2b | Does your implementation interpret the | always (7), |
| | decoded IRO as an ordered list always, | sometimes (1), |
| | sometimes or never? | never (1) |
| | | |
| 2c | What criteria do you use to decide if the | none (9) |
| | IRO is an ordered or unordered list? | |
| | | |
| 2d | Does your implementation interpret the IRO | strict (5), |
| | as a sequence of strict hops or as a | loose (2), both |
| | sequence of loose hops? | (2) |
+----+--------------------------------------------+-----------------+
Table 2: IRO Decoding
Regarding IRO decoding, most implementations interpret IRO as an
ordered list. More than half of implementation under survey consider
the IRO sub-objects as strict hops, others consider loose or support
both.
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+----+----------------------------------------------+---------------+
| | Questions | Response |
+----+----------------------------------------------+---------------+
| 3a | Will there be an impact to your | none (9) |
| | implementation if [RFC5440] is updated to | |
| | state that the IRO is an ordered list? | |
| | | |
| 3b | Will there be an impact to your | yes (5), no |
| | implementation if [RFC5440] is updated to | (4) |
| | state that the IRO is an unordered list? | |
| | | |
| 3c | will there be an impact to your | none (5), |
| | implementation if [RFC5440] is also updated | yes(1), yes- |
| | to allow IRO sub-objects to use the loose | but-small (3) |
| | bit (L-bit)? | |
+----+----------------------------------------------+---------------+
Table 3: Impact
It is interesting to note that most implementation that responded to
the survey finds that there is no impact to their existing or under-
development implementation if [RFC5440] is updated to state that the
IRO as an ordered list. Further most implementations find that
support for loose bit (L-bit) for IRO has minimal or no impact on
their implementation.
5. Conclusions
The results shown in this survey seems to suggest that most
implementations would be fine with updating [RFC5440] to specify IRO
as an ordered list with no impact on the shipping or under-
development products. It is also the conclusion of this survey to
suggest that it would be helpful to update [RFC5440] to enable
support for loose bit (L-bit) such that both strict and loose hops
could be supported in the IRO.
5.1. Proposed Action
The proposed action is as follows:
o Update [RFC5440] to specify IRO as an ordered list.
o Update [RFC5440] to specify support for loose bit (L-bit) for IRO.
o Remove the new IRO option from draft-ietf-pce-pcep-domain-
sequence-05.
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An update to IRO specification are proposed in
[I-D.dhody-pce-iro-update].
6. Security Considerations
This survey defines no protocols or procedures and so includes no
security-related protocol changes. Clarification in the supported
IRO ordering or loose bit handling will not have any negative
security impact. The survey responses in this document were
collected by email and that email was not authenticated, although
responses were sent to the respondents that might have triggered
alarms if the responses were spoofed. Spoofed or malicious responses
could represent an attack on the IETF process and so this survey
should be treated with some caution where there is reason to suspect
such an attack. Further, this survey was compiled and anonymized by
the working group chairs.
7. IANA Considerations
This informational document makes no requests to IANA for action.
8. Acknowledgments
A special thanks to author of [I-D.farrel-ccamp-ero-survey], this
document borrow some of the structure and text from it.
9. References
9.1. Normative References
[RFC5440] Vasseur, JP. and JL. Le Roux, "Path Computation Element
(PCE) Communication Protocol (PCEP)", RFC 5440, March
2009.
9.2. Informative References
[RFC5441] Vasseur, JP., Zhang, R., Bitar, N., and JL. Le Roux, "A
Backward-Recursive PCE-Based Computation (BRPC) Procedure
to Compute Shortest Constrained Inter-Domain Traffic
Engineering Label Switched Paths", RFC 5441, April 2009.
[I-D.ietf-pce-pcep-domain-sequence]
Dhody, D., Palle, U., and R. Casellas, "Standard
Representation Of Domain-Sequence", draft-ietf-pce-pcep-
domain-sequence-06 (work in progress), October 2014.
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[I-D.farrel-ccamp-ero-survey]
Farrel, A., "Informal Survey into Explicit Route Object
Implementations in Generalized Multiprotocol Labels
Switching Signaling Implementations", draft-farrel-ccamp-
ero-survey-00 (work in progress), May 2006.
[I-D.dhody-pce-iro-update]
Dhody, D., "Update to Include Route Object (IRO)
specification in Path Computation Element communication
Protocol (PCEP)", draft-dhody-pce-iro-update-01 (work in
progress), October 2014.
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Appendix A. Contributor Addresses
Julien Meuric
Orange
France
EMail: julien.meuric@orange.com
Jonathan Hardwick
Metaswitch
100 Church Street
Enfield EN2 6BQ
UK
EMail: jonathan.hardwick@metaswitch.com
Author's Address
Dhruv Dhody
Huawei Technologies
Leela Palace
Bangalore, Karnataka 560008
India
EMail: dhruv.ietf@gmail.com
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