.\" -*- nroff -*-
.\" =========================================================================
.\"
.\" @(#) draft-bidulock-sigtran-aspext-00.me,v 0.8 2002/04/02 08:10:53 brian Exp
.\"
.\" -------------------------------------------------------------------------
.\"
.\" Copyright (C) 2002  OpenSS7 Corporation <http://www.openss7.com>
.\"
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.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not have
.\" taken the same level of care in the production of this manual, which is
.\" licensed free of charge, as they might when working professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by the
.\" source, must acknowledge the copyright and authors of this work.
.\"
.\" -------------------------------------------------------------------------
.\"
.\" U.S. GOVERNMENT RESTRICTED RIGHTS.  If you are licensing this Software on
.\" behalf of the U.S. Government ("Government"), the following provisions
.\" apply to you.  If the Software is supplied by the Department of Defense
.\" ("DoD"), it is classified as "Commercial Computer Software" under
.\" paragraph 252.227-7014 of the DoD Supplement to the Federal Acquisition
.\" Regulations ("DFARS") (or any successor regulations) and the Government
.\" is acquiring only the license rights granted herein (the license rights
.\" customarily provided to non-Government users).  If the Software is
.\" supplied to any unit or agency of the Government other than DoD, it is
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.\" SS7preBetaRelease(0.8) modified 2002/04/02 08:10:53 by brian
.\"
.\" =========================================================================
.R1
abbreviate A
label L
no-default-database
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annotate X lp
move-punctuation
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join-authors ", " ", " " and "
et-al " et al" 2 3
search-truncate 10
separate-label-second-parts ""
bracket-label " [" "]" ", "
# abbreviate-label-ranges "..."
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# reverse A
.R2
.de $0
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.if \\$3<4 \{\
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.(l C F
\fI\\*(&f\\n(&n.\fR  \\$1
.(x 2
\\*(&f\\n(&n \\$1
.)x
.)l
.nr &p \\n(&n
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.ds a \a
.bp
.he 'Internet Draft'UA ASPEXT'January 10, 2002'
.TS
expand tab(;);
l c r.
Network Working Group;;Brian Bidulock
INTERNET-DRAFT;;OpenSS7 Corporation
.bl 2
Expires in six months;;January 10, 2002
.bl 2
.TE
.(l C
\fB\
Application Server Process (ASP) Extension (ASPEXT) Framework
for
Signalling User Adaptation Layers
<draft-bidulock-sigtran-aspext-00.\*(|x>

.)l
.rr |x
.ne 4
.uh "Status of this Memo"
.pp
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 or RFC 2026.  Internet-Drafts are working documents
of the Internet Engineering Task Force (IETF), its areas, and its working
groups.  Note that other groups may also distribute working documents as
Internet-Drafts.
.pp
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'.
.pp
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
.pp
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
.pp
To learn the current status of any Internet-Draft, please check the
'1id-abstracts.txt' listing contained in the Internet-Drafts Shadow
Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au
(Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast).
.uh "Abstract"
.pp
This Internet-Draft describes \fB\)ASP Extensions (ASPEXT)\fR for Signalling
User Adaptation Protocols,
.[
RFC 3057
.]
.[
dua-00
.]
.[
v5ua-01
.]
.[
m2ua-11
.]
.[
m3ua-10
.]
.[
sua-09
.]
.[
tua-01
.]
which permits cooperating Signalling Peer Processes (SPPs) to indicate to each
other the specific protocol extensions that each supports.
.sh 1 "Introduction"
.sh 2 "Scope"
.pp
This Internet-Draft provides parameters and procedures in extension to the
parameters and procedures of the Signalling User Adaptation Layers
(UAs),
.[
RFC 3057
.]
.[
dua-00
.]
.[
v5ua-01
.]
.[
m2ua-11
.]
.[
m3ua-10
.]
.[
sua-09
.]
.[
tua-01
.]
for the purpose of supporting a framework for extending the parameters and
procedures of these Adaptation Layers.
.pp
UA implementations with \fB\)ASPEXT\fR are intended to be
compatible with UA implementations not supporting this configuration.
.sh 2 "Terminology"
.pp
\fB\)ASPEXT\fR adds the following terms to the terminology presented
in the UA documents:
.lp
\fI\)ASP Extension\fR \-
.ix +\n(iiu
An extension to one or more of the the UAs that requires identification of the
capabilities of the SPP to support the extension as part of its requirements.
.lp
\fI\)Signalling Peer Process (SPP)\fR \-
.ix +\n(iiu
refers to an ASP, SGP or IPSP.
.lp
\fI\)Signalling User Adaptation Layer (UA)\fR \-
.ix +\n(iiu
one or more of the Stream Control Transmission Protocol (SCTP)
.[
sctp
.]
SS7 Signalling User Adaptation Layers
.[
RFC 3057
.]
.[
dua-00
.]
.[
v5ua-01
.]
.[
m2ua-11
.]
.[
m3ua-10
.]
.[
sua-09
.]
.[
tua-01
.]
supporting the concept of a \fI\)ASP Management\fR.
.sh 2 "Overview"
.pp
There is a need to provide extensions for the Signalling User Adaptation Layer
protocols that require interworking between Signalling Peer Processes (SPPs)
implementing a specific extension and SPPs not implementing the extension.
.pp
\fB\)ASPEXT\fR provides parameters and procedures that allow
Signalling Peer Processes (SPPs) implementing a given set of extensions to
indicate its support to other SPPs as well as to discover the support for
extensions provided by peer SPPs.
.sh 3 "Existing Extension Management"
.ds #u \*#
.pp
The existing UA procedures\*#
.(d
.ip \*#
See, for example, Section 4 of M3UA, SUA or TUA.
.[
m3ua-10
.]
.[
sua-09
.]
.[
tua-01
.]
.)d
make no provisions for the management of extensions.  Any mechanism that an
SPP might use to determine the extension support of peer SPPs depends upon
implementation dependent configuration information or protocols between SPPs.
.pp
For example, if an ASP implements and extension that requires that the ASP
have knowledge of whether a peer SGP supports the extension, the ASP would
have to be configured with this SGP-specific information, or would need to use
some implementation-dependent mechanism to determine this information.
.pp
The lack of an IETF procedure for managing extension support represents a
deficiency of the existing UA procedures\*(#u that detracts from
interoperability between separate implementations of SPP peers.
.sh 3 "ASP Extension Management"
.pp
\fB\)ASPEXT\fR provide support for the following:
.bu
Support for an SPP indicating to peer SPPs the extensions that are supported.
.bu
Support for an SPP discovering what extensions are supported by peer SPPs.
.bu
Support for an SPP supporting \fB\)ASPEXT\fR interworking with an SPP that
does not support \fB\)ASPEXT\fR.
.sh 1 "Conventions"
.pp
The keywords \fB\)MUST\fR, \fB\)MUST NOT\fR, \fB\)REQUIRED\fR, \fB\)SHALL\fR,
\fB\)SHALL NOT, \fB\)SHOULD\fR, \fB\)SHOULD NOT\fR, \fB\)RECOMMENDED\fR,
\fB\)NOT RECOMMENDED\fR, \fB\)MAY\fR, and \fB\)OPTIONAL\fR, when they appear
in this document, are to be interpreted as described in.
.[
key words
.]
.sh 1 "Protocol Elements"
.ds #w \*#
.pp
\fB\)ASPEXT\fR provides the following parameters and the messages in which
they are included in addition to the parameters of the UAs.\*#
.(d
.ip \*#
See, for example, Section 3 of the M3UA, SUA or TUA.
.[
m3ua-10
.]
.[
sua-09
.]
.[
tua-01
.]
.)d
.sh 2 "Parameters"
.pp
\fB\)ASPEXT\fR provides the following parameters in addition to the parameters
defined for the UAs.\*(#w
.sh 3 "ASP Extensions"
.pp
The \fI\)ASP Extensions\fR parameter is a common parameter used in the
\fB\)ASPUP\fR and \fB\)ASPUP ACK\fR messages to identify the extension
capabilities of the ASP (\fB\)ASPUP\fR) and the extension capabilities of the
SGP or IPSP (\fB\)ASPUP ACK\fR).
.pp
The \fI\)ASP Extensions\fR parameter is formatted as follows:
.(b
.(c
.nf
.sz -2
\fC\
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|         Tag = 0xXXXX          |            Length = 8         |
+- - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - -+
|                       ASP Extension #1                        |
+- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -+
|                       ASP Extension #2                        |
+- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -+
\\                               .                               \\
/                               .                               /
\\                               .                               \\
/                                                               /
+- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -+
|                       ASP Extension #n                        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.sz +2
.)c
.)b
.(q
.#v
\fB\)EDITOR'S NOTE:\-\fR\  The parameter tag values shown as \f(CB\)0xXXXX\fR
above will be assigned by IANA within the common parameter range of the
SIGTRAN UAs and may change its value in further versions of this document.
.)q
.pp
The \fI\)ASP Extensions\fR parameter contains one or more of the following
fields:
.ip "\fB\)ASP Extension field: 32-bits (unsigned integer)\fR" 2

The \fI\)ASP Extension\fR field contains an IANA registered extension
identifier number that identifies the extension supported by the ASP in an
\fB\)ASPUP\fR or an extension supported by the SGP or IPSP in an \fB\)ASPUP
ACK\fR.  Examples of valid values for the \fI\)ASP Extension\fR field are as
follows:
.ix +4
.TS
tab(:);
nl.
0:None
1:Load Selection Extension
.[
loadsel
.]
2:Correlation Id and Heartbeat Extension
.[
corid
.]
3:Session Identification Extension
.[
sessid
.]
\-:(All other values are IETF reserved.)
.TE
.ix -4
Each occurrence of an \fI\)ASP Extension\fR field indicates that the sending
SPP supports the specified extension.  The \fI\)ASP Extension\fR
parameter \fB\)MUST\fR contain at least one ASP Extension value.  An ASP
Extension field containing the value "None" \fB\)MUST\fR be the only ASP
Extension field included in the \fI\)ASP Extension\fR parameter.
.sh 2 "Messages"
.pp
\fB\)ASPEXT\fR extends the following messages defined for the UAs.\*(#w
.sh 3 "ASP Up (ASPUP)"
.pp
\fB\)ASPEXT\fR supplements the \fB\)ASPUP\fR message by permitting the
following optional parameters to be included in the message:
.ix +4
.TS
tab(:);
lbss
lw(2.5i)lc.
Extension Parameters
_
ASP Extensions:Optional:
.TE
.pp
The format of the resulting \fB\)ASPUP\fR message is as follows:
.(b
.(c
.nf
.sz -2
\fC\
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|         Tag = 0x0011          |            Length = 8         |
+- - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - -+
|                         ASP Identifier                        |
\f(CB\
+-------------------------------+-------------------------------+
|         Tag = 0xXXXX          |            Length = 8         |
+- - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - -+
\\                                                               \\
/                         ASP Extensions                        /
\\                                                               \\
+-------------------------------+-------------------------------+
\f(CR\
|         Tag = 0x0004          |            Length             |
+- - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - -+
\\                                                               \\
/                           Info String                         /
\\                                                               \\
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.sz +2
.)c
.)b
.(q
.#v
\fB\)EDITOR'S NOTE:\-\fR\  The parameter tag values shown as \f(CB\)0xXXXX\fR
above will be assigned by IANA within the common parameter range of the
SIGTRAN UAs and may change its value in further versions of this document.
.)q
.pp
No other changes to the \fB\)ASPUP\fR message format are provided by this
extension.
.pp
To indicate its support for a specific extension, the ASP \fB\)MUST\fR
include the specific extension number in the \fI\)ASP Extensions\fR parameter
in the \fB\)ASPUP\fR message.
.sh 3 "ASP Up Acknowledgment (ASPUP ACK)"
.pp
\fB\)ASPEXT\fR supplements the \fB\)ASPUP ACK\fR message by permitting
the following optional parameters to be included in the message:
.ix +4
.TS
tab(:);
lbss
lw(2.5i)lc.
Extension Parameters
_
ASP Extensions:Optional:
.TE
.pp
The format of the resulting \fB\)ASPUP ACK\fR message is as follows:
.(b
.(c
.nf
.sz -2
\fC\
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
\f(CB\
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|         Tag = 0xXXXX          |            Length = 8         |
+- - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - -+
\\                                                               \\
/                         ASP Extensions                        /
\\                                                               \\
+-------------------------------+-------------------------------+
\f(CR\
|         Tag = 0x0004          |            Length             |
+- - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - -+
\\                                                               \\
/                           Info String                         /
\\                                                               \\
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.sz +2
.)c
.)b
.(q
.#v
\fB\)EDITOR'S NOTE:\-\fR\  The parameter tag values shown as \f(CB\)0xXXXX\fR
above will be assigned by IANA within the common parameter range of the
SIGTRAN UAs and may change its value in further versions of this document.
.)q
.pp
No other changes to the \fB\)ASPUP ACK\fR message format are provided by this
extension.
.pp
To indicate its support for a specific extension, SGP and IPSP \fB\)MUST\fR
include the specific extension number in the \fI\)ASP Extensions\fR parameter
in the \fB\)ASPUP ACK\fR message.
.sh 1 "Procedures"
.pp
The following procedures are provided in extension to the UA procedures by
\fB\)ASPEXT\fR.
.sh 2 "ASP Management Procedures"
.sh 3 "ASP Up Procedures"
.pp
In extension of the "ASP Up Procedures" of the UAs\*(#u, \fB\)ASPEXT\fR
provides the following procedures:
.pp
Whenever and ASP, as part of the normal UA procedures, sends an ASP Up
(ASPUP) message to an SGP or IPSP it \fB\)MAY\fR include the \fI\)ASP
Extensions\fR parameter indicating the extensions supported by the ASP.
.pp
Upon receiving an ASP Up (ASPUP) message from an ASP that contains the
\fI\)ASP Extensions\fR parameter, an SGP or IPSP supporting \fB\)ASP
Extensions\fR \fB\)MUST\fR register the ASP's support of the specified
extensions and \fB\)MUST\fR place an \fI\)ASP Extensions\fR parameter of its
own in the responding ASP Up Acknowledgment (ASPUP ACK) indicating
which of the extensions provided in the \fB\)ASPUP\fR are supported.
.pp
If an SGP or IPSP supporting \fB\)ASPEXT\fR receives an \fB\)ASPUP\fR
message that does not contain an \fI\)ASP Extensions\fR parameter, the SGP or
IPSP \fB\)MAY\fR assume that the ASP does not support any extensions, or
\fB\)MAY\fR rely on internal configuration data to determine the extensions
supported by the ASP.  The SGP or IPSP \fB\)SHOULD NOT\fR include the \fI\)ASP
Extensions\fR parameter in the responding \fB\)ASPUP ACK\fR message.
.pp
Upon receiving an ASP Up Acknowledgment (ASPUP ACK) containing an
\fI\)ASP Extensions\fR parameter, an ASP supporting \fB\)ASPEXT\fR
\fB\)MUST\fR register the SGP or IPSP's support of the specified extensions.
.pp
If an SPP supporting \fB\)ASPEXT\fR receives an \fB\)ERR\fR message
indicating the \fI\)ASP Extensions\fR parameter as an "Invalid Parameter" in
response to an \fB\)ASPUP\fR or \fB\)ASPUP ACK\fR message, the SPP
\fB\)SHOULD\fR re-attempt sending the \fB\)ASPUP\fR or \fB\)ASPUP ACK\fR
message without the \fI\)ASP Extensions\fR parameter.
.sh 1 "Examples"
.sh 2 "Both ASP and SGP/IPSP support ASP Extensions"
.pp
\fI\*(&f\n(&n\fR illustrates an example where both the ASP and the SGP or IPSP
support \fB\)ASPEXT\fR.
.(b
.(c
.nf
.sz -2
\fC\
     ASP                                    SGP/IPSP
      |                                         |
 (1)  |      SCTP Association Established       |
      |<- - - - - - - - - - - - - - - - - - - ->|
      |                                         |
 (2)  |    ASPUP (Extensions: LOADSEL, CORID)   |
      |---------------------------------------->|
      |                                         |
 (3)  |     ASPUP ACK (Extensions: LOADSEL)     |
      |<--------------------------------------->|
      |                                         |
 (4)  |                                         |
      |                                         |
.sz +2
.)c
.#f "Both ASP and SGP/IPSP support ASP Extensions"
.)b
.pp
The example sequence of events for the example illustrated in \fI\)\*(&f\n(&p\fR is as follows:
.np
An SCTP Association is established or the ASP is otherwise in the ASP-DOWN
state.
.np
The ASP sends an ASPUP message to the SGP or IPSP containing an
\fI\)ASP Extensions\fR parameter identifying (for example) two
extensions: Load Selection
.[
loadsel
.]
and Correlation Id/Heartbeat;
.[
corid
.]
indicating the ASP's support for these two extensions requiring interworking
support.
.np
The SGP or IPSP responds with an ASPUP ACK message containing an \fI\)ASP
Extensions\fR parameter identifying (for example) support for only one
extension: Load Selection
.[
loadsel
.]
.np
The ASP and SGP/IPSP register the peer's support (or lack of support) for the
LOADSEL and CORID extensions and modify subsequent procedures accordingly.
.sh 2 "Interworking Examples"
.sh 3 "ASP supports ASP Extensions, SGP/IPSP does not"
.nr &u \n(&n+1
.pp
\fI\*(&f\n(&n\fR and \fI\n(&u\fR illustrate an example where the ASP supports
\fB\)ASPEXT\fR but the SGP or IPSP does not.
.(b
.(c
.nf
.sz -2
\fC\
     ASP                                    SGP/IPSP
      |                                         |
 (1)  |      SCTP Association Established       |
      |<- - - - - - - - - - - - - - - - - - - ->|
      |                                         |
 (2)  |    ASPUP (Extensions: LOADSEL, CORID)   |
      |---------------------------------------->|
      |                                         |
 (3)  |               ASPUP ACK                 |
      |<--------------------------------------->|
      |                                         |
 (4)  |                                         |
      |                                         |
.sz +2
.)c
.#f "ASP supports ASP Extensions, SGP/IPSP ignores"
.)b
.pp
The example sequence of events for the example illustrated in \fI\)\*(&f\n(&p\fR is as follows:
.np
An SCTP Association is established or the ASP is otherwise in the ASP-DOWN
state.
.np
The ASP sends an ASPUP message to the SGP or IPSP containing an
\fI\)ASP Extensions\fR parameter identifying (for example) two
extensions: Load Selection
.[
loadsel
.]
and Correlation Id/Heartbeat;
.[
corid
.]
indicating the ASP's support for these two extensions requiring interworking
support.
.np
The SGP or IPSP ignores the \fI\)ASP Extensions\fR parameter in the
\fB\)ASPUP\fR and responds with an \fB\)ASPUP ACK\fR message containing no
\fI\)ASP Extensions\fR parameter.
.np
The ASP either assumes that the SGP or IPSP does not support the LOADSEL or
CORID extensions, or relies upon configuration data to indicate the SGP or IPSP's
support for these extensions.  The ASP modifies its subsequent procedures with
regard to the extension accordingly.
.lp
.(b
.(c
.nf
.sz -2
\fC\
     ASP                                    SGP/IPSP
      |                                         |
 (1)  |      SCTP Association Established       |
      |<- - - - - - - - - - - - - - - - - - - ->|
      |                                         |
 (2)  |    ASPUP (Extensions: LOADSEL, CORID)   |
      |---------------------------------------->|
      |                                         |
 (3)  |         ERR("Invalid Parameter")        |
      |<--------------------------------------->|
      |                                         |
 (4)  |                 ASPUP                   |
      |---------------------------------------->|
      |                                         |
 (5)  |               ASPUP ACK                 |
      |<--------------------------------------->|
      |                                         |
 (6)  |                                         |
      |                                         |
.sz +2
.)c
.#f "ASP supports ASP Extensions, SGP/IPSP refuses"
.)b
.pp
The example sequence of events for the example illustrated in \fI\)\*(&f\n(&p\fR is as follows:
.np
An SCTP Association is established or the ASP is otherwise in the ASP-DOWN
state.
.np
The ASP sends an ASPUP message to the SGP or IPSP containing an
\fI\)ASP Extensions\fR parameter identifying (for example) two
extensions: Load Selection
.[
loadsel
.]
and Correlation Id/Heartbeat;
.[
corid
.]
indicating the ASP's support for these two extensions requiring interworking
support.
.np
The SGP or IPSP refuses to accept the \fI\)ASP Extensions\fR parameter in the
\fB\)ASPUP\fR message and response with an \fB\)ERR\fR("Invalid Parameter")
message indicating such.
.np
The ASP re-attempts by sending an \fB\)ASPUP\fR message without an \fI\)ASP
Extensions\fR parameter.
.np
The SGP or IPSP responds with an \fB\)ASPUP ACK\fR message containing no
\fI\)ASP Extensions\fR parameter.
.np
The ASP either assumes that the SGP or IPSP does not support the LOADSEL or
CORID extensions, or relies upon configuration data to indicate the SGP or
IPSP's support for these extensions.  The ASP modifies its subsequent
procedures with regard to the extension accordingly.
.sh 3 "SGP/IPSP supports ASP Extensions, ASP does not"
.pp
\fI\*(&f\n(&n\fR illustrates an example where the SGP or IPSP supports
\fB\)ASPEXT\fR but the ASP does not.
.(b
.(c
.nf
.sz -2
\fC\
     ASP                                    SGP/IPSP
      |                                         |
 (1)  |      SCTP Association Established       |
      |<- - - - - - - - - - - - - - - - - - - ->|
      |                                         |
 (2)  |                 ASPUP                   |
      |---------------------------------------->|
      |                                         |
 (3)  |               ASPUP ACK                 |
      |<--------------------------------------->|
      |                                         |
 (4)  |                                         |
      |                                         |
.sz +2
.)c
.#f "SGP/IPSP supports ASP Extensions, ASP ignores"
.)b
.pp
The example sequence of events for the example illustrated in \fI\)\*(&f\n(&p\fR is as follows:
.np
An SCTP Association is established or the ASP is otherwise in the ASP-DOWN
state.
.np
The ASP sends an ASPUP message to the SGP or IPSP not containing an
\fI\)ASP Extensions\fR parameter.
.np
The SGP or IPSP responds with an ASPUP ACK message not containing an \fI\)ASP
Extensions\fR parameter.
.np
The SGP either assumes that the ASP does not support the CORID extensions, or
relies upon configuration data to indicate the ASP's support for these
extensions.  The SGP modifies its subsequent procedures with regard to the
extension accordingly.
.sh 1 "Security"
.pp
\fB\)ASPEXT\fR do not introduce any new security risks or
considerations that are not already inherent in the UA
.[
RFC 3057
.]
.[
dua-00
.]
.[
v5ua-01
.]
.[
m2ua-11
.]
.[
m3ua-10
.]
.[
sua-09
.]
.[
tua-01
.]
Please see the "Security" sections of
IUA,
.[
RFC 3057
.]
DUA,
.[
dua-00
.]
V5UA,
.[
v5ua-01
.]
M2UA,
.[
m2ua-11
.]
M3UA,
.[
m3ua-10
.]
SUA
.[
sua-09
.]
and TUA,
.[
tua-01
.]
for security considerations and recommendations that are applicable to each of
these UAs.
.sh 1 "IANA Considerations"
.sh 2 "Extensions"
.pp
\fB\)ASPEXT\fR provides an additional \fI\)ASP Extensions\fR message
parameter to the common parameter range of the SIGTRAN UAs:
.[
RFC 3057
.]
.[
dua-00
.]
.[
v5ua-01
.]
.[
m2ua-11
.]
.[
m3ua-10
.]
.[
sua-09
.]
.[
tua-01
.]
.af $p a
.np
The parameter is named the \fI\)ASP Extensions\fR parameter.
.np
The structure of the \fI\)ASP Extensions\fR parameter field conforms to the UA
general TLV format and is described in detail in Section 3.1.1.
.np
The detailed definition of each component of the \fI\)ASP Extensions\fR
parameter values is described in Section 3.1.1.
.np
This document also provides a detailed description of the intended use of the
\fI\)ASP Extensions\fR parameter, and in which messages the \fI\)ASP
Extensions\fR parameter should appear, how many times, and when.
.lp
.(q
.#v
\fB\)EDITOR'S NOTE:\-\fR\  The \fI\)ASP Extensions\fR parameter tag value
shown throughout this document as \f(CB\)0xXXXX\fR will be assigned by IANA
within the common parameter range of the SIGTRAN UAs and may change its value
in further versions of this document.
.)q
.sh 2 "Protocol Extensions"
.pp
UA protocols may be extended through IANA in three ways:
.bu
through definition of additional message classes;
.bu
through definition of additional message types; and,
.bu
through definition of additional message parameters.
.pp
The definition and used of new message classes, types and parameters is an
integral part of the SIGTRAN adaptation layers.  Thus, these extensions are
assigned by IANA through an IETF Consensus action.
.[
rfc 2434
.]
.pp
The proposed extension \fB\)MUST\fR in no way adversely affect the general
working of the protocol.
.pp
To permit interoperability of implementations supporting a particular
extension with implementation not supporting that extension, a UA Extension
number can be assigned to a protocol extension in accordance with this
document.  A new registry will be created by IANA to allow:
.sh 3 "IETF Defined UA Protocol Extension"
.pp
In additional to the documentation required for each message class, message
type and message parameter extension, the documentation of the UA Protocol
Extension number \fB\)MUST\fR include the following information:
.af $p a
.np
A long and short name for the Extension.
.np
A detailed description of the the purpose of the Extension.
.np
A detailed description of the Message Classes, Types and Parameters provided
by the extension.
.np
A detailed description of the interworking between UA implementations
supporting the Extension and UA implementations not supporting the Extension.
.\".uh "Acknowledgments"
.\".pp
.\"The authors would like to thank
.\"for their valuable comments and suggestions.
.nr ii 0.5i
.if \n($d>1 \{\
.uh "End Notes"
.pd
.\}
.de ]<
.rm (f )f
..
.uh "References"
.[
$LIST$
.]
.(b
.uh "Author's Addresses"
.lp
.TS
expand tab(;);
lr.
Brian Bidulock;Phone: +1-972-839-4489
OpenSS7 Corporation;Email: bidulock@openss7.org
4701 Preston Park Boulevard;URL: http//www.openss7.org/
Suite 424;
Plano, TX  75093;
USA;
.TE
.bl 3
.lp
This Internet draft expires July, 2002.
.)b
.bp
.\".ce 1
.\".uh "List of Tables"
.\".(l I
.\".xp 3
.\".)l
.(b I
.(c
.ce 1
.uh "List of Illustrations"
.lp
.xp 2
.)c
.)b
.(b I
.(c
.ce 1
.uh "Table of Contents"
.lp
.xp 0
.)c
.)b
.bp
.uh "Copyright Statement"
.lp
\fBCopyright \(co The Internet Society (2002).  All Rights Reserved.\fR
.pp
This document and translations of it may be copied and furnished to others,
and derivative works that comment on or otherwise explain it or assist in its
implementation may be prepared, copied, published and distributed, in whole or
in part, without restriction of any kind, provided that the above copyright
notice and this paragraph are included on all such copies and derivative
works.  However, this document itself may not be modified in any way, such as
by removing the copyright notice or references to the Internet Society or
other Internet organizations, except as needed for the purpose of developing
Internet standards in which case the procedure for copyrights defined in the
Internet Standards process must be followed, or as required to translate into
languages other than English.
.pp
The limited permission granted above are perpetual and will not be revoked by
the Internet Society or its successors or assigns.
.pp
This document and the information contained herein is provided on an "AS IS"
basis and \fB\)THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE
DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS
OR ANY IMPLIED WARRANTIES OF MECHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE.
