[Docs] [txt|pdf] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02 03 04 05 06 07 08 09 RFC 3624

Internet Engineering Task Force                             B. Foster
Internet Draft                                            D. Auerbach
Document: <draft-foster-mgcp-bulkaudits-09.txt>          F. Andreasen
Category: Informational                                 Cisco Systems
                                                            June 2003


      The Media Gateway Control Protocol (MGCP) Bulk Audit Package

Status of this Document

  This document is an Internet-Draft and is in full conformance with
  all provisions of Section 10 of RFC2026

  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.

  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."

  The list of current Internet-Drafts can be accessed at
  http://www.ietf.org/ietf/1id-abstracts.txt

  The list of Internet-Draft Shadow Directories can be accessed at
  http://www.ietf.org/shadow.html.

Abstract

  The base Media Gateway Control Protocol (MGCP) includes audit
  commands that only allow a Call Agent to audit endpoint and/or
  connection state one endpoint at a time. This document describes a
  new MGCP package for bulk auditing of a group of gateway endpoints.
  It allows a Call Agent to determine the endpoint naming convention,
  the list of instantiated endpoints as well connection and endpoint
  state for the group of endpoints.

Conventions used in this document

  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 RFC-2119.











Foster et al.                Informational                     [Page 1]


                        MGCP Bulk Audit Package               June 2003

                            Table of Contents


1.0 Introduction......................................................2
2.0. Bulk Audit Package...............................................2
 2.1. Package Definition..............................................2
   2.1.1. Package Parameters..........................................3
   2.1.2. Bulk Auditing of Non-persistent Virtual Endpoints..........10
   2.1.3. Package Specific Return Codes..............................11
 2.2. Examples of Package Use........................................12
   2.2.1. Endpoint List..............................................12
   2.2.2. Connection Count List......................................12
   2.2.3. Connection Mode List.......................................14
   2.2.4. Endpoint State.............................................14
3.0. IANA Considerations.............................................16
5.0. Security Considerations.........................................16
6.0. References......................................................16
7.0. Authors' Addresses..............................................16
8.0. Full Copyright Statement........................................17







1.0 Introduction

  The reader is assumed to be familiar with the base MGCP protocol [3].

  The base Media Gateway Control Protocol (MGCP) [3] includes audit
  commands that only allow a Call Agent to audit endpoint and/or
  connection state, one endpoint at a time. This document describes a
  new MGCP package for bulk auditing of a group of gateway endpoints.
  It allows a Call Agent to determine the endpoint naming convention,
  to determine the list of instantiated endpoints and to determine the
  connection and endpoint state for the group of endpoints. This is
  particularly important in fail-over situations in which there are
  gateways that have large numbers of endpoints.


2.0. Bulk Audit Package

2.1. Package Definition

  Package Name: BA

  Package Version: 0

  Package Description: This package provides the Call Agent the ability
  to audit and obtain high-level view of endpoint and connection state
  for a group of endpoints in a gateway.



Foster et al.                Informational                     [Page 2]


                        MGCP Bulk Audit Package               June 2003

2.1.1. Package Parameters

  A new BulkRequestedInfo parameter is defined for use in the
  AuditEndpoint command. The parameter can be used to request a compact
  list of EndpointIds or to request a high level view of endpoint or
  connection state for a group of endpoints as defined below:

     ReturnCode,
     [EndPointNameList,]
     [InstantiatedEndpointList,]
     [ConnectionCountList,]
     [ConnectionModeList,]
     [EndpointStateList,]
     [NextEndpointName,]
     [ReportedEndpointList]
     <-- AuditEndPoint(EndpointId,
                         [StartEndpointName,]
                         [MaxNumEndpoints,]
                         [BulkRequestedInfo])

  Unlike the normal RequestedInfo parameter in the base MGCP
  specification, the BulkRequestedInfo parameter associated with the
  Bulk Audits package can be used with "all-of" wildcards for auditing
  a collection of endpoints. It is not an error to specify an
  EndpointId without wildcards, however.

  The following sub-sections describe the parameters associated with
  the Bulk Audit Command in detail. Sections 2.1.1.1 and 2.1.1.2
  describe the parameters that can be included with a request and
  sections 2.1.1.3 to 2.1.1.8 describe return parameters.

2.1.1.1. StartEndpointName and MaxNumEndpoints Parameters

  Because wild-carding may not be sufficient to qualify the endpoints
  of interest, further qualification can be provided by including a
  StartEndpointName (the first endpoint of interest) and
  MaxNumEndPoints (the maximum number of endpoints of interest). These
  parameters are described according to the following Augmented BNF
  (ABNF) Syntax (refer to RFC 2234 for ABNF syntax definitions [1]):

     "BA/SE" ":" 0*WSP LocalEndpointName

     "BA/NU" ":" 0*WSP MaxNumEndpoints

  where MaxNumEndpoints is the decimal number of endpoints with a value
  in the range 1 to 65535. The MaxNumEndpoints parameter SHOULD only be
  included when requesting an audit for an EndpointStateList and/or
  ConnectionCountList. If included in a request for the
  EndPointNameList or InstantiatedEndpointList, it MAY be ignored.

  Note that only the LocalEndpointName (see ABNF grammar in [3]) is
  provided in request and response parameter lines for this package
  rather than the full EndpointName. This is done for the sake of


Foster et al.                Informational                     [Page 3]


                        MGCP Bulk Audit Package               June 2003

  compactness, i.e. the domain name portion is left out since it is
  already available in the command line portion of a given request.

  If the list of endpoints defined by the StartEndpointName and
  MaxNumEndPoints is outside the range designated by the wild-carding,
  values a report will only be returned for endpoints up to those
  specified within the wild-card range.

2.1.1.2. BulkRequestedInfo Parameter

  The BulkRequestedInfo parameter line is described according to the
  following ABNF syntax definitions:

     BulkRequestedInfo = "BA/F:" 0*WSP
            *( EndpointOrInstantList *("," EndpointOrInstantList))
          / *( EndpointOrConnState *("," EndpointOrConnState))

     EndpointOrConnState = "BA/C" / "BA/M" /  EndpointStateParam

     EndpointOrInstantList = "BA/Z" / "BA/X"

     EndpointStateParam = "BA/S" "(" StateType
                                        0*("," 0*(WSP) StateType)")"

     StateType = "I" / "D" / "N" / "S" / "H"

  where the BulkRequestedInfo parameters have the following meaning:

     * "BA/Z" is a request to return EndPointNameList
     * "BA/X" is a request to return InstantiatedEndpointList
     * "BA/C" is a request to return the ConnectionCountList
     * "BA/M" is a request to return the ConnectionModeList
     * "BA/S" is a request to return the EndpointStateList

  Each of the parameters can be provided at most once in the
  BulkRequestedInfo.

  EndpointStateParam Parameter:

     As indicated in the above ABNF, the EndpointStateParam parameter
     is itself parameterized with one or more StateType parameters that
     define the conditions to be evaluated for the endpoint:

       * "I" - the endpoint is in-service,
       * "D" - the endpoint is disconnected (see sections 4.3 and
          4.4.7 of [3] for a discussion on disconnected endpoints),
       * "N" - the endpoint is in the notification state,
       * "L" - the endpoint is in lockstep state (i.e. waiting for an
          RQNT after a response to a NTFY has occurred while in
          lockstep mode)
       * "S" - there is an active on-off (OO) or timeout (TO) signal
          on the endpoint,
       * "H" - the endpoint is in some state other than "idle". The
          meaning of this last parameter depends on the type of

Foster et al.                Informational                     [Page 4]


                        MGCP Bulk Audit Package               June 2003

          endpoint:
          * The parameter has no meaning for endpoints that only
            provide bearer services (with no state that the endpoint is
            aware of). In this case, the condition is always evaluated
            to false (corresponding to "idle").
          * For endpoints that have a state machine associated with
            them (such as a CAS endpoint), the endpoint MUST be in some
            state other than the "idle" state in order for the
            condition to be evaluated as true.
          * In the case where the endpoint has hook-state associated
            with it, the hook-state MUST be off-hook. In the case of
            digital channel associated signaling (CAS) connections,
            hook-state may be provided in either direction. If the
            hook-state in either direction is off-hook, the endpoint is
            considered non-idle, i.e. the condition is satisfied.

     The list of StateTypes may be extended in the future. If an
     unknown StateType is encountered, the command MUST be rejected
     with error code 803 (i.e. "unsupported StateType").

     The report provided as a result of this request, yields an
     indication of either "True", "False", or "Out of Service" for each
     endpoint. If the endpoint is in-service and any one of the
     criteria holds true, then the report for the endpoint will
     evaluate to "True". A "False" indication will only be reported if
     the endpoint is in-service and all criteria evaluate to false. The
     report thus provides the logical "OR" function over the conditions
     audited for endpoints in-service. Irrespective of the state being
     audited, an "Out of Service" indication will always be reported if
     the endpoint is considered out-of-service.

     Note that the criteria "D", "N", "L", "S" and "H" can only be true
     if the endpoint is in-service, so that requesting "I" at the same
     time (although allowed) would be unnecessary (i.e. redundant).

  Example: If the request for EndpointStateList for one or more
  endpoints includes the parameter line:

     BA/F: BA/S(D,N)

  indicating a request for a report on whether endpoints are
  disconnected or in the notification state. If a given endpoint is in
  either a "disconnected" or "notification" state, then the report will
  indicate "True" for that endpoint. If the endpoint is neither in a
  disconnected state nor in a notification state, but is in-service,
  then the report for that endpoint will indicate "False". If the
  endpoint is out-of-service, then the report for that endpoint will
  indicate "Out of Service".

  In order to only determine whether an endpoint is in-service or out-
  of service, the Call Agent should make a request with only the "I"
  StateType parameter.



Foster et al.                Informational                     [Page 5]


                        MGCP Bulk Audit Package               June 2003



2.1.1.3. EndPointNameList and InstantiatedEndpointList Parameters

  EndPointNameList Parameter:

     The EndPointNameList is a list of the endpoint names (i.e. the
     endpoint naming convention for the endpoints configured for
     service) supported by the gateway as qualified by the wildcarded
     EndPointId, and possibly StartEndPointName and MaxNumEndpoints
     parameters. This list can include one or more lines in the
     following ABNF format:

      "BA/Z:" 0*WSP RangedLocalName 0*("," 0*WSP RangedLocalName)

     where RangedLocalName is a LocalEndpointName that may include the
     ranged wildcard notation described in Appendix E (section E.5) of
     [3], i.e.:

      RangeWildcard = "[" NumericalRange *( "," NumericalRange ) "]"
      NumericalRange     = 1*(DIGIT) [ "-" 1*(DIGIT) ].

     Example:

       ba/z: ds/ds1-1/[1-24], ds/ds1-2/[1-24], ds/ds1-3/[1-24]

     or simply:

       ba/z: ds/ds1-[1-3]/[1-24]

     Note that, since range wildcards use the character "[" to indicate
     the start of a range, the "[" character MUST NOT be used in
     endpoint names that use range wildcards.

     Note that the ranged wildcard notation (RangeWildcard above) also
     allows commas between ranges like:

       ba/z: ds/ds1-1/[1,3-5,8-24]

  For virtual endpoints, that are automatically created and deleted on
  the fly by the gateway, there is a difference between reporting the
  endpoint names (i.e. the "naming convention") used in describing the
  endpoints and reporting the actual endpoints that are instantiated at
  the time the request is made. For this case:

     * EndPointNameList is a request to return the naming convention
       and

     * InstantiatedEndpointList is a request to return the "real" (or
       instantiated) endpoints.

  InstantiatedEndpointList Parameter:



Foster et al.                Informational                     [Page 6]


                        MGCP Bulk Audit Package               June 2003

     The syntax of the InstantiatedEndpointList value is the same as
     the EndPointNameList value returned with EndPointNameList, i.e., a
     number of lines may be returned with the following syntax:

       "BA/X:" 0*WSP RangedLocalName 0*("," 0*WSP RangedLocalName)

  In the case of hard-wired/physical endpoints (such as DSO's) or other
  persistent endpoints, the InstantiatedEndpointList would normally not
  be requested. However, if it is requested, the
  InstantiatedEndpointList and the EndPointNameList will be the same.

  For virtual endpoints that are not persistent, an "all of" wild card
  ("*") is returned for the leftmost term of the name, which is
  dynamically assigned in the EndPointNameList to indicate that
  arbitrary names apply, and that the endpoints are virtual and non-
  persistent. The "all of" wild card notation MUST NOT be used when
  returning the EndPointNameList for persistent endpoints however. The
  following example illustrates this:

  ba/z: announcement/*
  ba/z: foo/bar/*
  ba/z: foo/foo/*

  The "all of" wildcard tells us, that "announcement" is simply the
  leftmost term for a dynamic set of non-persistent virtual endpoints.
  To instantiate one of these endpoints, we would include the "any of"
  wildcard (e.g. "announcement/$") as the LocalEndpointName in the
  EndpointId of a request (e.g. NotificationRequest or
  CreateConnection). The response would then include the
  SpecificEndpointId indicating the instantiated endpoint. Also note in
  the above example, that "foo" defines two different levels of non-
  persistent virtual endpoints.























Foster et al.                Informational                     [Page 7]


                        MGCP Bulk Audit Package               June 2003

2.1.1.4. ConnectionCountList

  The ConnectionCountList indicates the number of connections on a
  series of endpoints. It consists of a number of lines with the
  following ABNF syntax:

     "BA/C:" 0*WSP NumConnections 0*(NumConnections)

  where NumConnections is either:

     * a hexadecimal digit indicating the number of connections on the
       endpoint corresponding to the position on the list, or
     * the letter "Z" indicating that there are more than 15
       connections on this endpoint.

2.1.1.5. ConnectionModeList

  The ConnectionModeList indicates the connection modes for all the
  connections on a series of endpoints. It consists of a number of
  lines with the following ABNF syntax:

     "BA/M:" 0*WSP ModeOrCount 0*(ModOrCount)

     ModeOrCount = ConnCount / ConnMode

     ConnMode = "I" / "S" / "R" / "B" / "C" / "L" / "T" / "N" / "U"

  where ConnCount is either hexadecimal value corresponding to 0-15
  connections on an endpoint or the value "Z", indicating that more
  than 15 connections are present.

  ConnMode indicates the connection mode where:

       * "I" indicates "inactive" connection mode
       * "S" indicates "sendonly" connection mode
       * "R" indicates "recvonly" connection mode
       * "B" indicates "sendrecv" connection mode
       * "C" indicates "confrnce" connection mode
       * "L" indicates "loopback" connection mode
       * "T" indicates "conttest" connection mode
       * "N" indicates "netwloop" connection mode
       * "U" indicates some other connection mode

  For a definition of MGCP connection modes, refer to section 3.2.2.6
  of [3].

  If an endpoint has no connections on it, ModeOrCount is given the
  value "0". If there is one connection associated with the endpoint,
  the symbol for the connection mode (ConnMode) is provided. If on the
  other hand there are from 2 to 15 connections, a symbol representing
  the number of connections (ConnCount) is provided followed by a list
  of symbols indicating the connection mode (ConnMode) for each
  connection. If there are more than 15 connections, "Z" is indicated


Foster et al.                Informational                     [Page 8]


                        MGCP Bulk Audit Package               June 2003

  for ConnCount and no connection modes are provided for the
  connections on that endpoint.

2.1.1.6. EndpointStateList Parameter

  The EndpointStateList gives an overview of the endpoint state for a
  series of endpoints. It consists of a number of lines with the
  following ABNF syntax:

     "BA/S:" 0*WSP EndPointState 0*(EndPointState)

     EndPointState = "T" / "F" / "O"

  where:

     * "T" indicates "True"
     * "F" indicates "False"
     * "O" indicates "Out of Service"

  The "True" or "False" determination is based on the criteria supplied
  in StateType parameters when the request is made.

  Note that the EndPointState indicator does not say anything about the
  connection state of the endpoint.

2.1.1.7. NextEndpointName Parameter

  The NextEndpointName parameter will be included in the return, if
  there are additional endpoints in this gateway covered by the wild-
  carded endpoint name that were not reported, but for which
  information is available to be reported.

  Note that the NextEndpointName is the LocalEndpointName (as opposed
  to EndpointName) of the next endpoint after the last endpoint
  reported. The syntax is as follows:

     "BA/NE" ":" 0*WSP LocalEndpointName

  A gateway may supply a report that is shorter than the request if the
  resulting report would have resulted in a message that would be too
  large (i.e. such that the report is larger than the maximum datagram
  size). In the case where the gateway supplied a response for less
  endpoints than requested, the gateway MUST supply NextEndpointName in
  the response.

  In order to continue the audit on a following set of endpoints, the
  Call Agent can make a further request by using the NextEndpointName
  as the starting point (e.g. as the StartEndpointName in a following
  request).

2.1.1.8. ReportedEndpointList Parameter

  A ReportedEndpointList MUST be provided in a response line before
  list(s) of EndpointStateList and/or ConnectionCountList in order to

Foster et al.                Informational                     [Page 9]


                        MGCP Bulk Audit Package               June 2003

  clearly specify the list of endpoints that are being reported. The
  ABNF syntax is as follows:

  "BA/EL:" 0*WSP LimitedRangedName 0*("," 0*WSP LimitRangedName)

  where LimitedRangedName is a LocalEndpointName that may include a
  ranged wildcard notation (RangeWildcard syntax indicated earlier).
  However, unlike the RangedLocalName that allows the range wildcard
  notation to be used on multiple terms of the local name at the same
  time, LimitedRangedName only allows the range notation to be used for
  the last term, i.e. the following is valid:

     ba/el: ds/ds1-1/[1,3-5,8-24]

  or

     ba/el: ds/ds1-1/[1-24], ds/ds1-2/[1-24], ds/ds1-3/[1-24]

  However, the following is not valid:

     ba/el: ds/ds1-[1-3]/[1-24]

  Note that a single bulk audit request may include a request to return
  both ConnectionCountList and EndpointStateList. However, the
  resulting report that includes both MUST cover the same endpoints.

  A single bulk audit request may also include a request to return both
  EndPointNameList and InstantiatedEndpointList. However, requests for
  either an EndPointNameList and/or an InstantiatedEndpointList MUST
  NOT include a request for either ConnectionCountList or
  EndpointStateList.

2.1.2. Bulk Auditing of Non-persistent Virtual Endpoints

  Note that gateways that have non-persistent virtual endpoints may
  have instantiated endpoints that are disjoint with respect to the
  name space. The ReportedEndpointList in front of a
  ConnectionCountList and/or EndpointStateList describes exactly which
  endpoints are being reported.

  Example:

     A Call Agent requests to know about the EndPointNameList for the
     endpoints on a conference bridge:

     AUEP 1200 *@gw1.x.net MGCP 1.0
     BA/F: BA/Z

  Response:

     200 1200 OK
     ba/z: cnf/*



Foster et al.                Informational                    [Page 10]


                        MGCP Bulk Audit Package               June 2003

  This indicates the naming convention but in fact not all of these
  endpoints are instantiated. A request for the list of instantiated
  endpoints, i.e.:

     AUEP 1201 cnf/*@gw1.x.net MGCP 1.0
     BA/F: BA/X

  might yield:

     200 1201 OK
     ba/x: cnf/[1-3]
     ba/x: cnf/[6-12]

  indicating that only these particular endpoints are instantiated.

  Suppose the Call Agent now asks for the ConnectionCountList i.e.:

     AUEP 1202 cnf/*@gw1.x.net MGCP 1.0
     BA/F: BA/C

  The resulting instantiated virtual endpoints may be disjoint, which
  would be indicated by the ReportedEndpointList in front of the
  ConnectionCountList, e.g.:

     200 1202 OK
     ba/el: cnf/[1-3]
     ba/c: 035
     ba/el: cnf/[6-12]
     ba/c: 3450333

  or alternatively:

     200 1202 OK
     ba/el: cnf/[1-3], ba/el: cnf/[6-12]
     ba/c: 035
     ba/c: 3450333

  or

     200 1202 OK
     ba/el: cnf/[1-3], ba/el: cnf/[6-12]
     ba/c: 0353450333


2.1.3. Package Specific Return Codes

  The following return codes are specific to this package:

          800     Invalid NextEndpointName
          801     Invalid StartEndpointName
          802     Invalid or unsupported BulkRequestInfo Parameter
          803     Invalid or unsupported StateType
          804     Bulk Audit Type not supported

Foster et al.                Informational                    [Page 11]


                        MGCP Bulk Audit Package               June 2003

          805     Incorrectly specified endpoint range
          806     Requested StartEndpoint unknown or unavailable

  Note that package specific error codes includes the package name
  following the error code. For example, if error code 801 occurs in
  response to a request with a transaction ID of 1001 it would be sent
  as:

     801 1001 /BA

2.2. Examples of Package Use

2.2.1. Endpoint List

  This section contains examples of obtaining the list of endpoints.

  Example 1: This is an example of a gateway that contains a single OC3
  that contains a single level of hierarchy at the T1 level.

  The request is made:

     AUEP 1200 *@gw1.x.net MGCP 1.0
     BA/F: BA/Z

  This may result in a single "BA/Z" term with ranges specifying all of
  the endpoints.

     200 1200 OK
     ba/z: ds/ds1-[1-84]/[1-24]

  Example 2: In this example the gateway has 10 analog lines and a
  single T1. The same request is made as in example 1, but now the
  response is:

     200 1200 OK
     ba/z: aaln/[1-10]
     ba/z: ds/ds1-1/[1-24]

2.2.2. Connection Count List

  Example1: Audit the number of connections on endpoints of a single
  E1:

     AUEP 2111 ds/e1-3/*@gw1.net
     BA/F: BA/C

  Response:

     200 2111 OK
     BA/EL: ds/e1-3/[1-30]
     BA/C:  012111210001000001000001000010



Foster et al.                Informational                    [Page 12]


                        MGCP Bulk Audit Package               June 2003

  Example 2: Audit the number of connections on endpoints of a DS3:

     AUEP 1144 ds/ds3-1/*@gateway.net
     BA/F: BA/C

  Response:

     200 1144 OK
     BA/EL: ds/ds3-1/[1-192]
     BA/C:  010000010001000001000001
     BA/C:  001000000101000000001001
     :
     .
     BA/C:  011000100010000010000010
     BA/C:  011111010001000001000001
     BA/C:  011000001100000001000001
     BA/NE: ds/ds3-1/193

  In this case, the response provided by the gateway contained
  information about the first 192 endpoints. If the ds-3 contained a T1
  hierarchy, the "BA/EL" and "BA/NE" values would indicate that
  hierarchy e.g.:

     200 1144 OK
     BA/EL: ds/ds3-1/ds1-1/[1-24]
     BA/C:  010000010001000001000001
     BA/EL: ds/ds3-1/ds1-2/[1-24]
     BA/C:  001000000101000000001001
     :
     .
     BA/EL: ds/ds3-1/ds1-6/[1-24]
     BA/C:  011000100010000010000010
     BA/EL: ds/ds3-1/ds1-7/[1-24]
     BA/C:  011111010001000001000001
     BA/EL: ds/ds3-1/ds1-8/[1-24]
     BA/C:  011000001100000001000001
     BA/NE: ds/ds3-1/ds1-9/1

  The Call Agent could continue to request endpoints by indicating the
  starting endpoint where it left off, i.e. simply using the returned
  "BE/NE" value as the "BA/SE" value for the next request:

     AUEP 1145 ds/ds3-3/*@gw1.net
     BA/F: BA/C
     BA/SE: ds/ds3-1/ds1-9/1

  Example 3: In this case, the Call Agent wants to know about the
  connection state of 12 DS0's starting with the endpoint with the
  LocalEndpointName "ds/ds3-1/ds1-6/4":

Foster et al.                Informational                    [Page 13]


                        MGCP Bulk Audit Package               June 2003


     AUEP 1146 ds/ds3-1/*@gw1.net
     BA/F: BA/C
     BA/SE: ds/ds3-1/ds1-6/4
     BA/NU: 12

  Response:

     200 1144 OK
     BA/EL: ds/ds3-1/ds1-6/[4-15]
     BA/C:  011000010001
     BA/NE: ds/ds3-1/ds1-6/16

2.2.3. Connection Mode List

  Example: Audit the connection modes for connections on the endpoints
  of a single E1:

     AUEP 2111 ds/e1-3/*@gw1.net
     BA/F: BA/M

  Response:

     200 2111 OK
     BA/EL: ds/e1-3/[1-30]
     BA/M:  0R2BRBBB2RRB000B00000B00000B0000B0

  This shows that:

     * Endpoint ds/e1-3/1 has no connections
     * Endpoint ds/e1-3/2 has one connection and it is in "recvonly"
       mode.
     * Endpoint ds/e1-3/3 has two connections which are in "sendrecv"
       and "recvonly" mode
     * Endpoints ds/e1-3/4 to ds/e1-3/6 each have one connection - in
       "sendrecv" mode in all cases
     * Endpoints ds/e1-3/7 has two connections, both in "recvonly" mode
     * etc.

2.2.4. Endpoint State

  Endpoint state requests and responses are similar. An example of
  requesting endpoint state similar to example 3 in the previous
  section:

     AUEP 1150 ds/ds3-1/*@gw1.net
     BA/F: BA/S(I)
     BA/SE: ds/ds3-1/ds1-6/4
     BA/NU: 12

  Response:

Foster et al.                Informational                    [Page 14]


                        MGCP Bulk Audit Package               June 2003


     200 1150 OK
     BA/EL: ds/ds3-1/ds1-6/[4-15]
     BA/S:  TOOTTOOTTOOT
     BA/NE: ds/ds3-1/ds1-6/16

  The request for in-service endpoints returns "True" for all endpoints
  in-service, and "O" for all endpoints "Out of Service".

  A similar request but with additional parameters might be:

     AUEP 1151 ds/ds3-1/*@gw1.net
     BA/F: BA/S(H,N)
     BA/SE: ds/ds3-1/ds1-6/4
     BA/NU: 12

  Response:

     200 1151 OK
     BA/EL: ds/ds3-1/ds1-6/[4-15]
     BA/S:  FFFTFFFFFFFO
     BA/NE: ds/ds3-1/ds1-6/16

  This indicates that at least one of the StateType parameters "H"
  (off-hook) and "N" (notification state) evaluated to true for the
  endpoints that have a "T" associated with then (i.e. ds/ds3-1/ds1-6/7
  and ds/ds3-1/ds1-6/16 since the request started from ds/ds3-1/ds1-
  6/4). All other endpoints are neither off-hook nor in the
  "notification state". Note that endpoint ds/ds3-1/ds1-6/15 is marked
  as being out-of-service.

  It is possible to request both connection state and endpoint state in
  the same request such as:

     AUEP 1151 ds/ds3-1/*@gw1.net
     BA/F: BA/S(H,N), BA/C
     BA/SE: ds/ds3-1/ds1-6/4
     BA/NU: 12

  In this case, the response might be:

     200 1151 OK
     BA/EL: ds/ds3-1/ds1-6/[4-15]
     BA/S:  FFFTFFFFFFFO
     BA/C:  011000010001
     BA/NE: ds/ds3-1/ds1-6/16






Foster et al.                Informational                    [Page 15]


                        MGCP Bulk Audit Package               June 2003

3.0. IANA Considerations

  The MGCP package title "Bulk Audit" with the name "BA" should be
  registered with IANA as indicated in Appendix C.1 in [3].

5.0. Security Considerations

  Section 5 of the base MGCP specification [3] discusses security
  requirements for the base protocol, which apply equally to the
  package defined in this document. Use of a security Protocol such as
  IPsec (RFC 2401, RFC 2406) that provides per message authentication
  and integrity services is required in order to ensure that requests
  and responses are obtained from authenticated sources and that
  messages have not been modified.  Without such services, gateways and
  Call Agents are open to attacks.

  For example, although audit requests from unauthorized sources will
  not modify media gateway state, the information provided could be
  used to locate idle endpoints, which could then lead to making
  unauthorized calls. Similarly, an attack that modifies a response to
  an audit returned to a Call Agent could lead to a denial of service
  attack in which a Call Agent that is provided misinformation as to
  endpoint state could take some incorrect action such as taking valid
  calls out of service.

6.0. References

  [1] D. Crocker & P. Overell, "Augmented BNF for Syntax Specificatins:
      ABNF", RFC 2234, November 1997

  [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
      Levels", BCP 14, RFC 2119, March 1997.

  [3] F. Andreasen, B. Foster "Media Gateway Control Protocol (MGCP)
      Version 1.0", RFC 3435, January 2003

7.0. Authors' Addresses

  Flemming Andreasen
  Cisco Systems
  499 Thornall Street, 8th Floor
  Edison, NJ 08837
  EMail: fandreas@cisco.com

  David Auerbach
  Cisco Systems
  771 Alder Dr.
  Milipitas, CA, 95035
  EMail: dea@cisco.com

  Bill Foster
  Cisco Systems
  EMail: bfoster@cisco.com


Foster et al.                Informational                    [Page 16]


                        MGCP Bulk Audit Package               June 2003


8.0. Full Copyright Statement

  Copyright (C) The Internet Society (2003).  All Rights Reserved.

  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 procedures for
  copyrights defined in the Internet Standards process must be
  followed, or as required to translate it into languages other than
  English.

  The limited permissions granted above are perpetual and will not be
  revoked by the Internet Society or its successors or assigns.

  This document and the information contained herein is provided on an
  "AS IS" basis and 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
  MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

  Acknowledgement

  Funding for the RFC Editor function is currently provided by the
  Internet Society.






















Foster et al.                Informational                    [Page 17]


Html markup produced by rfcmarkup 1.129c, available from https://tools.ietf.org/tools/rfcmarkup/