draft-ietf-stir-rph-01.txt   draft-ietf-stir-rph-02.txt 
STIR R. Singh STIR R. Singh
Internet-Draft Vencore Labs Internet-Draft Vencore Labs
Intended status: Standards Track M. Dolly Intended status: Standards Track M. Dolly
Expires: March 18, 2018 AT&T Expires: July 8, 2018 AT&T
S. Das S. Das
Vencore Labs Vencore Labs
A. Nguyen A. Nguyen
Office of Emergency Communication/DHS Office of Emergency Communication/DHS
September 14, 2017 January 04, 2018
PASSporT Extension for Resource-Priority Authorization PASSporT Extension for Resource-Priority Authorization
draft-ietf-stir-rph-01 draft-ietf-stir-rph-02
Abstract Abstract
This document extends the PASSporT object to convey This document extends the STIR PASSporT specification to allow the
cryptographically-signed assertions of authorization for inclusion of cryptographically-signed assertions of authorization for
communications 'Resource-Priority'. It extends PASSporT to allow the values populated in the SIP 'Resource-Priority' header field,
cryptographic-signing of the SIP 'Resource-Priority" header field which is used for communications resource prioritization.
which is used for communications resource prioritization. It also
describes how the PASSPorT extension is used in SIP signaling to
convey assertions of authorization of the information in the SIP
'Resource-Priority' header field.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 18, 2018. This Internet-Draft will expire on July 8, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
skipping to change at page 2, line 28 skipping to change at page 2, line 22
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. PASSporT 'rph' Claim . . . . . . . . . . . . . . . . . . . . 3 3. PASSporT 'rph' Claim . . . . . . . . . . . . . . . . . . . . 3
4. 'rph' in SIP . . . . . . . . . . . . . . . . . . . . . . . . 4 4. 'rph' in SIP . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. Authentication Service Behavior . . . . . . . . . . . . . 4 4.1. Authentication Service Behavior . . . . . . . . . . . . . 4
4.2. Verification Service Behavior . . . . . . . . . . . . . . 5 4.2. Verification Service Behavior . . . . . . . . . . . . . . 5
5. Further Information Associated with Resource-Priority . . . . 6 5. Further Information Associated with Resource-Priority . . . . 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
6.1. JSON Web Token Claims Registration . . . . . . . . . . . 6 6.1. JSON Web Token Claims Registration . . . . . . . . . . . 6
6.2. PASSporT 'rph' Types . . . . . . . . . . . . . . . . . . 6 6.2. PASSporT 'rph' Types . . . . . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7.1. Avoidance of replay and cut and past attacks . . . . . . 7 7.1. Avoidance of replay and cut and paste attacks . . . . . . 7
7.2. Solution Considerations . . . . . . . . . . . . . . . . . 7 7.2. Solution Considerations . . . . . . . . . . . . . . . . . 7
7.3. Acknowledgements . . . . . . . . . . . . . . . . . . . . 7 7.3. Acknowledgements . . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . 8 8.1. Normative References . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . 8 8.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction 1. Introduction
PASSporT [I-D.ietf-stir-passport] is a token format based on JWT PASSporT [I-D.ietf-stir-passport] is a token format based on JWT
[RFC7519] for conveying cryptographically-signed information about [RFC7519] for conveying cryptographically-signed information about
the identities involved in personal communications; it is used with the identities involved in personal communications; it is used with
STIR [I-D.ietf-stir-rfc4474bis] to convey a signed assertion of the STIR [I-D.ietf-stir-rfc4474bis] to convey a signed assertion of the
identity of the participants in real-time communications established identity of the participants in real-time communications established
via a protocol like SIP. This specification extends PASSporT to via a protocol like SIP. This specification extends PASSporT to
allow cryptographic-signing of the SIP 'Resource-Priority' header allow cryptographic-signing of the SIP 'Resource-Priority' header
field defined in [RFC4412]. field defined in [RFC4412].
[RFC4412] defines the SIP 'Resource-Priority' header field for [RFC4412] defines the SIP 'Resource-Priority' header field for
communications Resource Priority. As specified in [RFC4412], the communications Resource Priority. As specified in [RFC4412], the
'Resource-Priority' header field may be used by SIP user agents, 'Resource-Priority' header field may be used by SIP user agents
including, Public Switched Telephone Network (PSTN) gateways and [RFC3261], including, Public Switched Telephone Network (PSTN)
terminals, and SIP proxy servers to influence prioritization afforded gateways and terminals, and SIP proxy servers to influence
to communication sessions,including PSTN calls. However, the SIP prioritization afforded to communication sessions,including PSTN
'Resource-Priority' header field could be spoofed and abused by calls. However, the SIP 'Resource-Priority' header field could be
unauthorized entities. spoofed and abused by unauthorized entities.
The STIR architecture assumes that an authority on the originating The STIR architecture [RFC7340]assumes that an authority on the
side of a call provides a cryptographic assurance of the validity of originating side of a call provides a cryptographic assurance of the
the calling party number in order to prevent impersonation attacks. validity of the calling party number in order to prevent
The STIR architecture allows extension that can be utilized by impersonation attacks. The STIR architecture allows extension that
authorities supporting real-time communication services using the can be utilized by authorities supporting real-time communication
'Resource-Priority' header field to cryptographically sign the SIP services using the 'Resource-Priority' header field to
'Resource-Priority' header field and convey assertion of the cryptographically sign the SIP 'Resource-Priority' header field and
authorization for 'Resource-Priority'. For example, the authority on convey assertion of the authorization for 'Resource-Priority'. For
the originating side verifying the authorization of a particular example, the authority on the originating side verifying the
communication for Resource-Priority can use a PASSPorT claim to authorization of a particular communication for Resource-Priority can
cryptographically-sign the SIP 'Resource-Priority' header field and use a PASSPorT claim to cryptographically-sign the SIP 'Resource-
convey an assertion of the authorization for 'Resource-Priority'. Priority' header field and convey an assertion of the authorization
This will allow a receiving entity (including entities located in for 'Resource-Priority'. This will allow a receiving entity
different network domains/boundaries) to verify the validity of (including entities located in different network domains/boundaries)
assertions authorizating Resource-Priority. Cryptographically-signed to verify the validity of assertions authorizing Resource-Priority.
SIP 'Resource-Priority' headers will allow a receiving entity to Cryptographically-signed SIP 'Resource-Priority' headers will allow a
verify and act on the information with confidence that the receiving entity to verify and act on the information with confidence
information have not been spoofed or compromised. that the information have not been spoofed or compromised.
This specification documents an optional extension to PASSporT and This specification documents an optional extension to PASSporT and
the associated STIR mechanisms to provide a function to sign the SIP the associated STIR mechanisms to provide a function to sign the SIP
'Resource-Priority' header field. This PASSporT object is used to 'Resource-Priority' header field. This PASSporT object is used to
provide attestation of a calling user authorization for priority provide attestation of a calling user authorization for priority
communications. This is necessary in addition to the PASSporT object communications. This is necessary in addition to the PASSporT object
that is used for calling user telephone number attestation. How the that is used for calling user telephone number attestation. How the
optional extension to PASSporT is used for real-time communications optional extension to PASSporT is used for real-time communications
supported using SIP 'Resource-Priority' header field is defined in supported using SIP 'Resource-Priority' header field is defined in
other documents and is outside the scope of this document. other documents and is outside the scope of this document.
skipping to change at page 4, line 4 skipping to change at page 3, line 47
3. PASSporT 'rph' Claim 3. PASSporT 'rph' Claim
This specification defines a new JSON Web Token claim for "rph", This specification defines a new JSON Web Token claim for "rph",
which provides an assertion for information in SIP 'Resource- which provides an assertion for information in SIP 'Resource-
Priority'header. Priority'header.
The creator of a PASSporT object adds a "ppt" value of "rph" to the The creator of a PASSporT object adds a "ppt" value of "rph" to the
header of a PASSporT object, in which case the PASSporT claims MUST header of a PASSporT object, in which case the PASSporT claims MUST
contain a "rph" claim, and any entities verifying the PASSporT object contain a "rph" claim, and any entities verifying the PASSporT object
will be required to understand the "ppt" extension in order to will be required to understand the "ppt" extension in order to
process the PASSporT in question. A PASSPort header with the "ppt" process the PASSporT in question. A PASSPorT header with the "ppt"
included will look as follows: included will look as follows:
{ "typ":"passport", { "typ":"passport",
"ppt":"rph", "ppt":"rph",
"alg":"ES256", "alg":"ES256",
"x5u":"https://www.example.org/cert.cer"} "x5u":"https://www.example.org/cert.cer"}
The "rph" claim will provide an assertion of authorization,"auth", The "rph" claim will provide an assertion of authorization,"auth",
for information in the SIP "Resource-Priority" header field (i.e., for information in the SIP "Resource-Priority" header field (i.e.,
Resource-Priority: namespace "." r-priority) based on [RFC4412]. Resource-Priority: namespace "." r-priority) based on [RFC4412].
Specifically, the "rph" claim includes assertion of the priority- Specifically, the "rph" claim includes assertion of the priority-
level of the user to be used for a given communication session. The level of the user to be used for a given communication session. The
value of the "rph" claim is an array containing one or more of JSON value of the "rph" claim is an array containing one or more of JSON
objects for the content of the SIP 'Resource-Priority' header that is objects for the content of the SIP 'Resource-Priority' header that is
being asserted of which one of the "rph" object, is mandatory. being asserted of which one of the "rph" object, is mandatory.
The following is an example "rph" claim for a SIP "Resource-Priority" The following is an example "rph" claim for a SIP "Resource-Priority"
header field with a "namespace "." r-priority" value of "ets.0". header field with a "namespace "." r-priority" value of "ets.0" and
with a "namespace "." r-priority" value of "wps.0".
{ "orig":{"tn":"12155551212"} { "orig":{"tn":"12155551212"}
"dest":{"tn":"12125551213"}, "dest":{["tn":"12125551213"]},
"iat":1443208345, "iat":1443208345,
"rph":{"auth":"ets.0"}} "rph":{"auth":["ets.0","wps.0"]}
After the header and claims PASSporT objects have been constructed, After the header and claims PASSporT objects have been constructed,
their signature is generated normally per the guidance in their signature is generated normally per the guidance in
[I-D.ietf-stir-passport] using the full form of PASSPorT. The [I-D.ietf-stir-passport] using the full form of PASSPorT. The
credentials (e.g., authority responsible for authorizating Resource- credentials (e.g., authority responsible for authorizing Resource-
Priority) used to create the signature must have authority over the Priority) used to create the signature must have authority over the
"rph" claim and there is only one authority per claim. The authority "rph" claim and there is only one authority per claim. The authority
MUST use its credentials (i.e., CERT) associated with the specific MUST use its credentials (i.e., CERT) associated with the specific
service supported by the SIP namespace in the claim. service supported by the SIP namespace in the claim.
4. 'rph' in SIP 4. 'rph' in SIP
This section specifies SIP-specific usage for the "rph" claim in This section specifies SIP-specific usage for the "rph" claim in
PASSporT. PASSporT.
4.1. Authentication Service Behavior 4.1. Authentication Service Behavior
The Authentication Service will create the "rph" claim using the The Authentication Service will create the "rph" claim using the
values discussed in section 3 based on [RFC4412]. The construction values discussed in section 3 based on [RFC4412]. The construction
of "rph" claim follows the steps described in Section 4 of of "rph" claim follows the steps described in Section 4 of
[I-D.ietf-stir-rfc4474bis]. [I-D.ietf-stir-rfc4474bis].
The resulting Identity header for "rph" might look as follows: The resulting Identity header for "rph" might look as follows:
"eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJleUowZVhBaU9pSndZWE56Y0c5eW "eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJleUowZVhBaU9pSnd
RDSXNEUW9pY0hCMElqb2ljbkJvSWl3TkNpSmhiR2NpT2lKRlV6STFOaUlzRFFvaWVEVjFJanBvZE ZWE56Y0c5eWRDSXNEUW9pY0hCMElqb2ljbkJvSWl3TkNpSmhiR2NpT2lKRlV6STFO
hSd2N6b3ZMM2QzZHk1bGVHRnRjR3hsTG1OdmJTOWpaWEowTG1ObGNuME5DZz09IHx84oCZLuKAmX aUlzRFFvaWVEVjFJanBvZEhSd2N6b3ZMM2QzZHk1bGVHRnRjR3hsTG1OdmJTOWpaW
x8IGV5SnZjbWxuSWpwN0luUnVJam9pTVRJeE5UVTFOVEV5TVRJaWZTd2dEUW9pYVdGMElqb2lNVF EowTG1ObGNuME5DZzBLIHx84oCZLuKAmXx8IGV5QWliM0pwWnlJNmV5SjBiaUk2SW
EwTXpJd09ETTBOU0lzSUEwS0ltUmxjM1FpT25zaWRHNGlPaUl4TWpFMU5UVTFNVEl4TXlKOURRb2 pFeU1UVTFOVFV4TWpFeUluME5DaUprWlhOMElqcDdXeUowYmlJNklqRXlNVEkxTlR
ljbkJvSWpwN0ltRjFkR2dpT2lKbGRITXVNQ0o5RFFvTkNnMEsgICAgIiwibmJmIjoxNDk4NDg5MT VeE1qRXpJbDE5TEEwS0ltbGhkQ0k2TVRRME16SXdPRE0wTlN3TkNpSnljR2dpT25z
U5LCJleHAiOjE0OTg0OTI3NTksImlhdCI6MTQ5ODQ4OTE1OX0.oia2-qJTlDJICsJ_Af2A5slhO2 aVlYVjBhQ0k2V3lKbGRITXVNQ0lzSW5kd2N5NHdJbDE5RFFvPSJ9.s37S6VC8HM6D
iJU-kAHG-HRVVhRiUea6acIoD0w2Bc3Ap4iZ6izx7haRj55MtKKCwY5_bItA"; l6YzJeQDsrZcwJ0lizxhUrA7f_98oWBHvo-cl-n8MIhoCr18vYYFy3blXvs3fslM_
info= "https://www.example.org/cert.cer";alg=ES256;ppt="rph" oos2P2Dyw"; info= "https://www.example.org/cert.cer";alg=ES256;
ppt="rph"
A SIP authentication service typically will derive the value of "rph" A SIP authentication service typically will derive the value of "rph"
from the 'Resource-Priority' header field based on policy associated from the 'Resource-Priority' header field based on policy associated
with service specific use of the "namespace "." r-priority" values with service specific use of the "namespace "." r-priority" values
based on [RFC4412]. The authentication service derives the value of based on [RFC4412]. The authentication service derives the value of
the PASSPorT claim by verifying the authorization for Resource- the PASSPorT claim by verifying the authorization for Resource-
Priority (i.e., verifying a calling user privilege for Resource- Priority (i.e., verifying a calling user privilege for Resource-
Priority based on its identity) which might be derived from customer Priority based on its identity) which might be derived from customer
profile data or from access to external services. profile data or from access to external services.
skipping to change at page 5, line 48 skipping to change at page 5, line 49
follows: follows:
The verification service MUST extract the value associated with the The verification service MUST extract the value associated with the
"auth" key in a full form PASSPorT with a "ppt" value of "rph". If "auth" key in a full form PASSPorT with a "ppt" value of "rph". If
the signature validates, then the verification service can use the the signature validates, then the verification service can use the
value of the "rph" claim as validation that the calling party is value of the "rph" claim as validation that the calling party is
authorized for Resource-Priority, which would in turn be used for authorized for Resource-Priority, which would in turn be used for
priority treatment in accordance with local policy for the associated priority treatment in accordance with local policy for the associated
communication service. communication service.
The verification service MUST extract the value associated with the
"auth" key in a full form PASSPorT with a "ppt" value of "rph". If
the signature validates, then the verification service can use the
value of the "rph" claim as validation that the calling party is
authorized for Resource-Priority, which would in turn be used for
priority treatment in accordance with local policy for the associated
communication service.
In addition, [I-D.ietf-stir-rfc4474bis] Section 6.2 Step 4 requires In addition, [I-D.ietf-stir-rfc4474bis] Section 6.2 Step 4 requires
"iat" value in "rph" claim to be verified. "iat" value in "rph" claim to be verified.
The behavior of a SIP UAs upon receiving an INVITE containing a The behavior of a SIP UAs upon receiving an INVITE containing a
PASSporT object with a "rph" claim will largely remain a matter of PASSporT object with a "rph" claim will largely remain a matter of
implementation policy for the specific communication service. In implementation policy for the specific communication service. In
most cases,implementations would act based on confidence in the most cases,implementations would act based on confidence in the
veracity of this information. The use of the compact form of veracity of this information. The use of the compact form of
PASSporT is not specified in this document. PASSporT is not specified in this document.
skipping to change at page 6, line 41 skipping to change at page 6, line 36
have one or more such additional information field(s). Details of have one or more such additional information field(s). Details of
such "rph" claim to encompass other data elements are left for future such "rph" claim to encompass other data elements are left for future
version of this specification. version of this specification.
6. IANA Considerations 6. IANA Considerations
6.1. JSON Web Token Claims Registration 6.1. JSON Web Token Claims Registration
o Claim Name: "rph" o Claim Name: "rph"
o Claim Description: Resource Priority Header o Claim Description: Resource Priority Header Authorization
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3 of [RFCThis] o Specification Document(s): Section 3 of [RFCThis]
6.2. PASSporT 'rph' Types 6.2. PASSporT 'rph' Types
This document requests that the IANA add a new entry to the PASSporT This document requests that the IANA add a new entry to the PASSporT
Types registry for the type "rph" which is specified in [RFCThis]. Types registry for the type "rph" which is specified in [RFCThis].
This specification also requests that the IANA create a new registry This specification also requests that the IANA create a new registry
for PASSporT "rph" types. Registration of new PASSporT "rph" types for PASSporT "rph" types. Registration of new PASSporT "rph" types
shall be under the specification required policy. This registry is shall be under the specification required policy. This registry is
to be initially populated with a single value for "auth" which is to be initially populated with a single value for "auth" which is
specified in [RFCThis]. specified in [RFCThis].
7. Security Considerations 7. Security Considerations
The security considerations discussed in [I-D.ietf-stir-rfc4474bis] The security considerations discussed in [I-D.ietf-stir-rfc4474bis]
in Section 10 are applicable here. in Section 10 are applicable here.
7.1. Avoidance of replay and cut and past attacks 7.1. Avoidance of replay and cut and paste attacks
The PASSporT extension with a "ppt" value of "rph" MUST only be sent The PASSporT extension with a "ppt" value of "rph" MUST only be sent
with SIP INVITE when 'Resource-Priority' header is used to convey the with SIP INVITE when 'Resource-Priority' header is used to convey the
priority of the communication as defined in [RFC4412]. To avoid the priority of the communication as defined in [RFC4412]. To avoid the
replay, and cut and paste attacks, the procedures described in replay, and cut and paste attacks, the procedures described in
Section 10.1 of [I-D.ietf-stir-rfc4474bis] MUST be followed. Section 10.1 of [I-D.ietf-stir-rfc4474bis] MUST be followed.
7.2. Solution Considerations 7.2. Solution Considerations
The use of extension to PASSporT tokens with "ppt" value "rph" based The use of extension to PASSporT tokens with "ppt" value "rph" based
skipping to change at page 8, line 37 skipping to change at page 8, line 32
<http://www.rfc-editor.org/info/rfc7519>. <http://www.rfc-editor.org/info/rfc7519>.
8.2. Informative References 8.2. Informative References
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E. A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261, Schooler, "SIP: Session Initiation Protocol", RFC 3261,
DOI 10.17487/RFC3261, June 2002, DOI 10.17487/RFC3261, June 2002,
<http://www.rfc-editor.org/info/rfc3261>. <http://www.rfc-editor.org/info/rfc3261>.
[RFC6919] Barnes, R., Kent, S., and E. Rescorla, "Further Key Words
for Use in RFCs to Indicate Requirement Levels", RFC 6919,
DOI 10.17487/RFC6919, April 2013,
<http://www.rfc-editor.org/info/rfc6919>.
[RFC7340] Peterson, J., Schulzrinne, H., and H. Tschofenig, "Secure [RFC7340] Peterson, J., Schulzrinne, H., and H. Tschofenig, "Secure
Telephone Identity Problem Statement and Requirements", Telephone Identity Problem Statement and Requirements",
RFC 7340, DOI 10.17487/RFC7340, September 2014, RFC 7340, DOI 10.17487/RFC7340, September 2014,
<http://www.rfc-editor.org/info/rfc7340>. <http://www.rfc-editor.org/info/rfc7340>.
Authors' Addresses Authors' Addresses
Ray P. Singh Ray P. Singh
Vencore Labs Vencore Labs
150 Mount Airy Road 150 Mount Airy Road
New Jersey, NJ 07920 New Jersey, NJ 07920
USA USA
Email: rsingh@vencorelabs.com Email: rsingh@vencorelabs.com
Martin Dolly Martin Dolly
AT&T AT&T
200 Laurel Avenue 200 Laurel Avenue
Middletown, NJ 07748 Middletown, NJ 07748
USA USA
Email: md3135@att.com Email: md3135@att.com
Subir Das Subir Das
Vencore Labs Vencore Labs
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