< draft-polk-local-emergency-rph-namespace-02.txt   draft-polk-local-emergency-rph-namespace-05.txt >
Network Working Group James Polk Network Working Group J. Polk
Internet-Draft Cisco Systems Internet-Draft Cisco Systems
Expires: January 12, 2013 July 12, 2012 Intended status: Informational February 22, 2013
Intended Status: Standards Track Expires: August 26, 2013
IANA Registering a SIP Resource Priority Header Field IANA Registering a SIP Resource Priority Header Field Namespace for
Namespace for Local Emergency Communications Local Emergency Communications
draft-polk-local-emergency-rph-namespace-02 draft-polk-local-emergency-rph-namespace-05.txt
Abstract Abstract
This document creates the new Session Initiation Protocol (SIP) This document creates the new Session Initiation Protocol (SIP)
Resource Priority header field namespace "esnet" for local emergency Resource Priority header field namespace 'esnet' for local emergency
usage to a public safety answering point (PSAP), between PSAPs, and session establishment to a public safety answering point (PSAP),
between a PSAP and first responders and their organizations, and between PSAPs, and between a PSAP and first responders and their
places this namespace in the IANA registry. organizations, and places this namespace in the IANA registry.
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-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six Internet-Drafts are draft documents valid for a maximum of six months
months and may be updated, replaced, or obsoleted by other documents and may be updated, replaced, or obsoleted by other documents at any
at any time. It is inappropriate to use Internet-Drafts as time. It is inappropriate to use Internet-Drafts as reference
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 January 12, 2013. This Internet-Draft will expire on August 26, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2013 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
(http://trustee.ietf.org/license-info) in effect on the date of (http://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 carefully, as they describe your rights and restrictions with respect
respect to this document. Code Components extracted from this to this document. Code Components extracted from this document must
document must include Simplified BSD License text as described in include Simplified BSD License text as described in Section 4.e of
Section 4.e of the Trust Legal Provisions and are provided without the Trust Legal Provisions and are provided without warranty as
warranty as described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Rules of Usage of the Resource Priority Header . . . . . . . 3 2. Rules of Usage of the Resource Priority Header field . . . . . 4
3. "esnet" Namespace Definition . . . . . . . . . . . . . . . . 5 3. "esnet" Namespace Definition . . . . . . . . . . . . . . . . . 7
3.1 Namespace Definition Rules and Guidelines . . . . . . . . 5 3.1. Namespace Definition Rules and Guidelines . . . . . . . . 7
3.2 The "esnet" Namespace . . . . . . . . . . . . . . . . . . 5 3.2. The 'esnet' Namespace . . . . . . . . . . . . . . . . . . 7
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
4.1 IANA Resource-Priority Namespace Registration . . . . . . 6 4.1. IANA Resource-Priority Namespace Registration . . . . . . 8
4.2 IANA Priority-Value Registrations . . . . . . . . . . . . 6 4.2. IANA Priority-Value Registrations . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 7. Normative References . . . . . . . . . . . . . . . . . . . . . 9
7.1 Normative References . . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.2 Informative References . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . 8
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].
1. Introduction 1. Introduction
This document creates the new Session Initiation Protocol (SIP) This document creates the new Session Initiation Protocol (SIP)
Resource Priority header field namespace "esnet" for local emergency Resource Priority header (RPH) field namespace 'esnet' for local
usage and places this namespace in the IANA registry. The SIP emergency usage and places this namespace in the IANA registry. The
Resource-Priority header field is defined in RFC 4412 [RFC4412]. SIP Resource-Priority header field is defined in RFC 4412 [RFC4412].
The new "esnet" namespace is to be used for inbound calls towards a The new 'esnet' namespace is to be used for inbound calls towards a
public safety answering point (PSAP), between PSAPs, and between a public safety answering point (PSAP), between PSAPs, and between a
PSAP and first responders or their organizations within managed IP PSAP and first responders or their organizations within managed IP
networks. This namespace is not envisioned for use on the open networks. This namespace is not for use on the open public Internet
public Internet because it can be trivially forged. because it can be trivially forged.
This new namespace can be included in SIP requests to provide an Adding a RPH with the 'esnet' namespace can be differentiated from
explicit priority indication within controlled environments, such as the marking of an emergency call using a service urn as defined in
an IMS infrastructure or Emergency Services network (ESInet) where RFC 5031 in that the RPH specifically requests preferential treatment
misuse can be reduced to a minimum because these types of networks in networks which honor it, while the marking merely identifies an
have great controls in place. The function is to facilitate emergency call without necessarily affecting resources allocated to
differing treatment of emergency SIP requests according to local it. It is appropriate to use both where applicable. RPH with
policy, or more likely, a contractual agreement between the network 'esnet' may also be used within public safety networks for SIP
organizations. This indication is used solely to differentiate sessions that are not emergency calls and thus not marked per RFC
certain SIP requests, transactions or dialogs, from other SIP 5031.
requests, transactions or dialogs that do not have the need for
priority treatment. If there are differing, yet still
understandable and valid Resource-Priority header values in separate
SIP requests, then this indication can be used by local policy to
determine which SIP request, transaction or dialog receives which
treatment (likely better or worse than another).
It can also be imagined that Application Service Providers (ASP) This new namespace is included in SIP requests to provide an explicit
directly attached to an ESInet can have a trust relationship with priority indication within controlled environments, such as an IMS
the ESInet such that within these networks, SIP requests (thereby infrastructure or Emergency Services network (ESInet) where misuse
the session(s) they establish) make use of this "esnet" namespace can be reduced to an acceptable level because these types of networks
for appropriate treatment. have controls in place. The function facilitates differing treatment
of emergency SIP requests according to local policy, or more likely,
a contractual agreement between the network organizations. This
indication is used solely to differentiate certain SIP requests,
transactions or dialogs, from other SIP requests, transactions or
dialogs that do not have the need for priority treatment. If there
are differing, yet still understandable and valid Resource-Priority
header values in separate SIP requests, then this indication can be
used by local policy to determine which SIP request, transaction or
dialog receives which treatment (likely better or worse than
another).
Application Service Providers (ASP) securely connected to an ESInet
may have sufficient controls policing the header, and a trust
relationship with the entities inside the ESInet. SIP requests from
such ASPs could make use of this 'esnet' namespace for appropriate
treatment when requests are passed from the ASP to the ESInet.
The 'esnet' namespace may also be used on calls from a PSAP or other
public safety agency on an ESInet towards a private or public
network, ASP or UA ("call back") when priority is needed. Again, the
request for priority is not for use on the public Internet due to the
ease of forging the header.
This document merely creates the namespace, per the rules within This document merely creates the namespace, per the rules within
[RFC4412], necessitating a Standards Track RFC for IANA registering [RFC4412] as updated by [I-D.rosen-rph-reg-policy], necessitating
new RPH namespaces and their relative priority-value order. IETF review for IANA registering new RPH namespaces and their
relative priority-value order.
There is the possibility that within emergency services networks a There is the possibility that within emergency services networks a
Multilevel Precedence and Preemption (MLPP)-like behavior can be Multilevel Precedence and Preemption (MLPP)-like behavior can be
achieved (likely without the 'preemption' part), provided local achieved (likely without the 'preemption' part), provided local
policy supports enabling this function,. This will ensure more the policy supports enabling this function. For example, calls placed
important calls are established or retained; therefore the "esnet" between law enforcement agents could be marked similarly to MLPP
namespace is given five priority-levels instead of just one. systems used by military networks, and some of those calls could be
MLPP-like SIP signaling is not defined in this document for handled with higher priority than an emergency call from an ordinary
911/112/999 style emergency calling, but it is not prevented either. user. Therefore the 'esnet' namespace is given five priority-levels
instead of just one. MLPP-like SIP signaling is not defined in this
document for 911/112/999 style emergency calling, but it is not
prevented either.
Within the ESInet, there will be emergency calls requiring different Within the ESInet, there will be emergency calls requiring different
treatments, according to the type of call. Does a citizen's call to treatments, according to the type of call. Does a citizen's call to
a PSAP require the same, a higher or a lower relative priority than a PSAP require the same, a higher or a lower relative priority than a
a PSAP's call to a police department, or the police chief? What PSAP's call to a police department, or the police chief? What about
about either relative to a call from within the ESInet to a either relative to a call from within the ESInet to a national
federal government's department of national security, such as the US government's department responsible for public safety, disaster
Department of Homeland Security? For these additional reasons, the relief, national security/defense, etc.? For these additional
"esnet" namespace was given multiple priority levels. reasons, the 'esnet' namespace was given multiple priority levels.
This document does not define any of these behaviors, outside of This document does not define any of these behaviors, outside of
reminding readers that the rules of RFC 4412 apply - though examples reminding readers that the rules of RFC 4412 apply - though examples
of usage are included for completeness. This document IANA of usage are included for completeness. This document IANA registers
registers the "esnet" RPH namespace for use within any emergency the 'esnet' RPH namespace for use within any emergency services
services networks, not just of those from citizens to PSAPs. networks, not just of those from citizens to PSAPs.
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].
2. Rules of Usage of the Resource Priority Header field 2. Rules of Usage of the Resource Priority Header field
This document retains the behaviors of the SIP Resource Priority This document retains the behaviors of the SIP Resource Priority
header field, defined in [RFC4412], during the treatment options header field, defined in [RFC4412], during the treatment options
surrounding this new "esnet" namespace. The usage of the "esnet" surrounding this new 'esnet' namespace. The usage of the 'esnet'
namespace does not have a 'normal', or routine call level, given the namespace does not have a 'normal', or routine call level, given the
environment this is to be used within (i.e., within an ESInet). environment this is to be used within (i.e., within an ESInet). That
That is for local jurisdictions to define within their respective is left for local jurisdictions to define within their respective
parts of the ESInet, which could be islands of local administration. parts of the ESInet, which could be islands of local administration.
RFC 4412 states that modifying the relative priority ordering or the The 'esnet' namespace MUST only be used where at least one end of the
number of priority-values to a registered namespace SHOULD NOT occur signaling, setting aside the placement of B2BUAs, is within a local
within the same administrative domain due to interoperability issues emergency organization. In other words, if either the originating
with dissimilar implementations and backwards compatibility of past human caller's UA, or the destination human callee's UA is part of
configurations. the local emergency organization, this is a valid use of 'esnet'.
The "esnet" namespace MUST only be used in times of an emergency,
where at least one end, setting aside the placement of B2BUAs, of
the signaling is within a local emergency organization. In other
words, if either the originating human caller's UA, or the
destination human callee's UA is part of the local emergency
organization, this is a valid use of "esnet".
The "esnet" namespace has 5 priority-values, in a specified relative The 'esnet' namespace has 5 priority-values, in a specified relative
priority order, and is registered as a queue-based namespace in priority order, and is registered as a queue-based namespace in
compliance with [RFC4412]. Individual jurisdictions MAY configure compliance with [RFC4412]. SIP entities that support preemption
their SIP entities for preemption treatment. This is OPTIONAL, treatment (see Section 5 of [RFC4412]) can be configured according to
subject to local policy decisions. local policy. Display names for the 'esnet' values displayed can
likewise be set according to local policy.
The following network diagram provides one example of local policy The following network diagram provides one example of local policy
choices for the use of the "esnet" namespace: choices for the use of the 'esnet' namespace:
|<-"esnet" namespace->| |<-'esnet' namespace->|
| *WILL* be used | | is used |
"esnet" namespace | ,-------. 'esnet' namespace | ,-------.
usage out of scope | ,' `. usage out of scope | ,' `.
|<------------>|<---"esnet" namespace ---->| / \ |<------------>|<---'esnet' namespace ---->| / \
+----+ | can be used +-----+ | ESInet | +----+ | can be used +-----+ | ESInet |
| UA |--- | --------------------|Proxy|-+ ------ | | UA |--- | --------------------|Proxy|-+ ------ |
+----+ \ | / +-----+ | | +----+ \ | / +-----+ | |
\ ,-------+ ,-------. | | +------+ | \ ,-------+ ,-------. | | +------+ |
+----+ ,' `. ,' `. | | |PSAP-1| | +----+ ,' `. ,' `. | | |PSAP-1| |
| UA |--- / User \ / Application \ | | +------+ | | UA |--- / User \ / Application \ | | +------+ |
+----+ ( Network +---+ Service )| | | +----+ ( Network +---+ Service )| | |
\ / \ Provider / | | +------+ | \ / \ Provider / | | +------+ |
+----+ /`. ,' `. .+-----+ | |PSAP-2| | +----+ /`. ,' `. .+-----+ | |PSAP-2| |
| UA |---- '-------' '-------' |Proxy|-+ +------+ | | UA |---- '-------' '-------' |Proxy|-+ +------+ |
+----+ | +-----+ | | +----+ | +-----+ | |
| | | | | | | |
+----+ | +-----+ | +------+ | +----+ | +-----+ | +------+ |
| UA |--- | --------------------|Proxy|-+ |PSAP-3| | | UA |--- | --------------------|Proxy|-+ |PSAP-3| |
+----+ \ | / +-----+ | +------+ | +----+ \ | / +-----+ | +------+ |
\ ,-------+ ,-------. | | | \ ,-------+ ,-------. | | |
+----+ ,' `. ,' `. | | | +----+ ,' `. ,' `. | | |
| UA |--- / User \ / Application \ | | +------+ | | UA |--- / User \ / Application \ | | +------+ |
+----+ ( Network +---+ Service )| | |PSAP-4| | +----+ ( Network +---+ Service )| | |PSAP-4| |
\ / \ Provider / | | +------+ | \ / \ Provider / | | +------+ |
+----+ /`. ,' `. .+-----+ | | +----+ /`. ,' `. .+-----+ | |
| UA |---- '-------' '-------' |Proxy|-+ ANY can | | UA |---- '-------' '-------' |Proxy|-+ ANY can |
+----+ | +-----+ | xfer/call | +----+ | +-----+ | xfer/call |
| | \ | | | / | | \ | | | /
`. | | | ,' `. | | | ,'
'-|-|-|-' '-|-|-|-'
| | | | | |
Police <--------------+ | | Police <--------------+ | |
Fire <----------+ | Fire <----------+ |
Federal Agency <-------+ National Agency <-------+
Figure 1: A possible network architecture using "esnet" namespace A possible network architecture using 'esnet' namespace
In Figure 1., the "esnet" namespace is intended for usage within the In Figure 1., the 'esnet' namespace is used within the ESInet on the
ESInet on the right side of the diagram. How it is specifically right side of the diagram. How it is specifically utilized is out of
utilized is out of scope for this document, and left to local scope for this document, and left to local jurisdictions to define.
jurisdictions to define. Adjacent ASPs to the ESInet MAY have a Whether preemption is implemented in the ESInet and the values
trust relationship that includes allowing this/these neighboring displayed to the ESInet users, is likewise out of scope. Adjacent
ASP(s) to use the "esnet" namespace to differentiate SIP requests ASPs to the ESInet may have a trust relationship that includes
and dialogs within the ASP's network. The exact mapping between the allowing this/these neighboring ASP(s) to use the 'esnet' namespace
internal and external sides of the edge proxy at the ESInet to differentiate SIP requests and dialogs within the ASP's network.
boundaries is out of scope of this document. The exact mapping between the internal and external sides of the edge
proxy at the ESInet boundaries is out of scope of this document.
3. "esnet" Namespace Definition 3. "esnet" Namespace Definition
The "esnet" namespace SHOULD NOT to be considered generic for all The 'esnet' namespace is not generic for all emergencies because
emergencies because there are a lot of different kinds of there are a lot of different kinds of emergencies, some on a military
emergencies, some on a military scale ([RFC4412] defines 3 of scale ([RFC4412] defines 3 of these), some on a national scale
these), some on a national scale ([RFC4412] defines 2 of these), ([RFC4412] defines 2 of these), some on an international scale. Each
some on an international scale. Each type of emergency can also type of emergency can also have its own namespace(s), and although
have its own namespace(s), and although there are 45 defined for there are many defined for other uses, more are possible - so the
other uses, more are possible - so the 911/112/999 style of public 911/112/999 style of public user emergency calling for police or fire
user emergency calling for police or fire or ambulance (etc) does or ambulance (etc) does not have a monopoly on the word "emergency".
not have a monopoly on the word "emergency".
The namespace "esnet" has been chosen, roughly to stand for The namespace 'esnet' has been chosen, roughly to stand for
"Emergency Services NETwork", for a citizen's call for help from a "Emergency Services NETwork", for a citizen's call for help from a
public authority type of organization. This namespace will also be public authority type of organization. This namespace will also be
used for communications between emergency authorities, and MAY be used for communications between emergency authorities, and MAY be
used for emergency authorities calling public citizens. An example used for emergency authorities calling public citizens. An example
of the latter is a PSAP operator calling back someone who previously of the latter is a PSAP operator calling back someone who previously
called 911/112/999 and the communication was terminated before it - called 911/112/999 and the communication was terminated before it -
in the PSAP operator's judgment - should have been. in the PSAP operator's judgment - should have been.
Here is an example of a Resource-Priority header field using the Here is an example of a Resource-Priority header field using the
"esnet" namespace: 'esnet' namespace:
Resource-Priority: esnet.0 Resource-Priority: esnet.0
3.1. Namespace Definition Rules and Guidelines 3.1. Namespace Definition Rules and Guidelines
This specification defines one unique namespace for emergency This specification defines one unique namespace for emergency calling
calling scenarios, "esnet", constituting its registration with IANA. scenarios, 'esnet', constituting its registration with IANA. This
This IANA registration contains the facets defined in Section 9 of IANA registration contains the facets defined in Section 9 of
[RFC4412]. [RFC4412].
3.2. The "esnet" Namespace 3.2. The 'esnet' Namespace
Per the rules of [RFC4412], each namespace has a finite set of Per the rules of [RFC4412], each namespace has a finite set of
relative priority-value(s), listed (below) from lowest priority to relative priority-value(s), listed (below) from lowest priority to
highest priority. In an attempt to not limit this namespace's use highest priority. In an attempt to not limit this namespace's use in
in the future, more than one priority-value is assigned to the the future, more than one priority-value is assigned to the 'esnet'
"esnet" namespace. This document does not recommend which namespace. This document does not recommend which Priority-value is
Priority-value is used where in which situation or scenario. That used where in which situation or scenario. That is for another
is for another document to specify. This document does RECOMMEND document to specify. To be effective, the choice within a national
the choice within a national jurisdiction be coordinated by all jurisdiction needs to be coordinated by all sub-jurisdictions to
sub-jurisdictions to maintain uniform SIP behavior throughout an maintain uniform SIP behavior throughout an emergency calling system
emergency calling system of that country. of that nation
The relative priority order for the "esnet" namespace is as follows: The relative priority order for the 'esnet' namespace is as follows:
(lowest) esnet.0 (lowest) esnet.0
esnet.1 esnet.1
esnet.2 esnet.2
esnet.3 esnet.3
(highest) esnet.4 (highest) esnet.4
The "esnet" namespace will be designated into the priority queuing The 'esnet' namespace will have priority queuing registrations for
algorithm (Section 4.5.2 of [RFC4412]). However, as a policy these levels per Section 4.5.2 of [RFC4412]. Although no preemption
decision, local jurisdiction(s) MAY configure their SIP is specified in this document for any levels of esnet, local
infrastructure to use the this namespace in a preemption algorithm jurisdiction(s) MAY configure their SIP infrastructure to use this
way, defined in RFC 4412. This document does not recommend this namespace with preemption, as defined in RFC 4412.
usage, but it is permissible according to this specification.
The remaining rules originated in RFC 4412 apply with regard to an The remaining rules originated in RFC 4412 apply with regard to an RP
RP actor, who understands more than one namespace, and MUST maintain actor who understands more than one namespace, and is must maintain
its locally significant relative priority order. its locally significant relative priority order.
4. IANA Considerations 4. IANA Considerations
4.1 IANA Resource-Priority Namespace Registration 4.1. IANA Resource-Priority Namespace Registration
Within the "Resource-Priority Namespaces" of the sip-parameters Within the "Resource-Priority Namespaces" of the sip-parameters
section of IANA (created by [RFC4412]), the following entries will section of IANA (created by [RFC4412]), the following entries will be
be added to this table: added to this table:
Intended New warn- New resp. Intended New warn- New resp.
Namespace Levels Algorithm code code Reference Namespace Levels Algorithm code code Reference
--------- ------ -------------- --------- --------- --------- --------- ------ -------------- --------- --------- ---------
esnet 5 queue no no [This doc] esnet 5 queue no no [This doc]
4.2 IANA Priority-Value Registrations 4.2. IANA Priority-Value Registrations
Within the Resource-Priority Priority-values registry of the Within the Resource-Priority Priority-values registry of the sip-
sip-parameters section of IANA, the following (below) is to be added parameters section of IANA, the following (below) is to be added to
to the table: the table:
Namespace: esnet Namespace: esnet
Reference: (this document) Reference: (this document)
Priority-Values (least to greatest): "0", "1","2", "3", "4" Priority-Values (least to greatest): "0", "1","2", "3", "4"
5. Security Considerations 5. Security Considerations
The Security considerations that apply to RFC 4412 [RFC4412] apply The Security considerations that apply to RFC 4412 [RFC4412] apply
here. here.
Within a network that is enabled to act on the Resource-Priority For networks that act on the SIP Resource-Priority header field,
header field within SIP requests, the implications of using this incorrect use of namespaces can result in traffic that should have
namespace within the field incorrectly can potentially cause a large been given preferential treatment not be given it and vice versa.
impact on a network, given that this indication is to give This document does not define a use case where an endpoint outside
preferential treatment of marked traffic great preference within the the ESInet marks its call for preferential treatment. Protections
network verses other traffic. This document does not indicate this need to be taken to prevent granting preferential treatment to
marking is intended for use by endpoints, yet protections need to be unauthorized users not calling for emergency help even if they are in
taken to prevent granting preferential treatment to unauthorized the ESInet, as well as to prevent misuse by callers outside the
users not calling for emergency help. ESInet.
A simple means of preventing this usage into an ESInet is to not A simple means of preventing this usage is to not allow 'esnet'
allow "esnet" marked traffic to get preferential treatment unless marked traffic to get preferential treatment unless the destination
the destination is towards the local/regional ESInet. This is not a is towards the local/regional ESInet. This is not a consideration
consideration for internetwork traffic within the ESInet, or for internetwork traffic within the ESInet, or generated out of the
generated out of the ESInet. 911/112/999 type of calling is fairly ESInet. 911/112/999 type of calling is fairly local in nature, with a
local in nature, with a finite number of URIs that are likely to be finite number of URIs that are likely to be considered valid within a
considered valid within a portion of a network receiving SIP portion of a network receiving SIP signaling.
signaling.
This namespace is not intended for use on the Internet because of the
difficulty in detecting abuse, specifically, it can trivially be
forged and used on a non-emergency session to obtain resource
priority. Some networks may determine that it can reasonably prevent
abuse and/or the consequences of undetected abuse is not significant.
In such cases, use of esnet MAY be allowed.
6. Acknowledgements 6. Acknowledgements
Thanks to Ken Carlberg, Janet Gunn, Fred Baker and Keith Drage for Thanks to Ken Carlberg, Janet Gunn, Fred Baker and Keith Drage for
help and encouragement with this effort. Thanks to Henning help and encouragement with this effort. Thanks to Henning
Schulzrinne, Ted Hardie, Hannes Tschofenig, Brian Rosen, Janet Gunn Schulzrinne, Ted Hardie, Hannes Tschofenig, Janet Gunn and Marc
and Marc Linsner for constructive comments. A big thanks to Robert Linsner for constructive comments. A big thanks to Robert Sparks for
Sparks for being patient with the author. being patient with the author and Brian Rosen for completing the
final edits.
7. References
7.1 Normative References 7. Normative References
[RFC2119] S. Bradner, "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997 Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4412] Schulzrinne, H., Polk, J., "Communications Resource [RFC4412] Schulzrinne, H. and J. Polk, "Communications Resource
Priority for the Session Initiation Protocol (SIP)", RFC Priority for the Session Initiation Protocol (SIP)",
4411, Feb 2006 RFC 4412, February 2006.
7.2 Informative References [RFC5031] H. Schulzrinne, "A Uniform Resource Name (URN) for
Emergency and Other Well-Known Services", RFC 5031,
January 2008
none [I-D.rosen-rph-reg-policy]
Rosen, B., "Resource Priority Header (RPH) Registry
Management Policy to IETF Review",
draft-rosen-rph-reg-policy-00 (work in progress),
February 2013.
Author's Address Author's Address
James Polk James Polk
Cisco Systems
3913 Treemont Circle 3913 Treemont Circle
Colleyville, Texas 76034 Colleyville, TX 76034
USA USA
Phone: +1-817-271-3552 Phone: +1-817-271-3552
Email: jmpolk@cisco.com Email: jmpolk@cisco.com
 End of changes. 53 change blocks. 
233 lines changed or deleted 256 lines changed or added

This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/