SIPREC Ram Mohan. Ravindranath Internet-Draft Parthasarathi. Ravindran Intended status: Standards Track Paul. Kyzivat Expires: July 24, 2011 Cisco Systems, Inc. January 20, 2011 Session Initiation Protocol (SIP) Recording Metadata draft-ram-siprec-metadata-03 Abstract Session recording is a critical requirement in many communications environments such as call centers and financial trading. In some of these environments, all calls must be recorded for regulatory, compliance, and consumer protection reasons. Recording of a session is typically performed by sending a copy of a media stream to a recording device. This document describes the metadata model as viewed by Session Recording Server(SRS). Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on July 24, 2011. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must Ravindranath, et al. Expires July 24, 2011 [Page 1] Internet-Draft SIP Recording Metadata January 2011 include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Metadata Model . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Recording Metadata elements . . . . . . . . . . . . . . . . . 5 4.1. Recording Session . . . . . . . . . . . . . . . . . . . . 5 4.1.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 5 4.1.2. Associations . . . . . . . . . . . . . . . . . . . . . 6 4.2. Communication Session Group . . . . . . . . . . . . . . . 6 4.2.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 6 4.2.2. Associations . . . . . . . . . . . . . . . . . . . . . 6 4.3. Communication Session . . . . . . . . . . . . . . . . . . 7 4.3.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 7 4.3.2. Associations . . . . . . . . . . . . . . . . . . . . . 8 4.4. Participant . . . . . . . . . . . . . . . . . . . . . . . 8 4.4.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 9 4.4.2. Associations . . . . . . . . . . . . . . . . . . . . . 9 4.5. Media Stream . . . . . . . . . . . . . . . . . . . . . . . 10 4.5.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 10 4.5.2. Associations . . . . . . . . . . . . . . . . . . . . . 11 4.6. Application Data . . . . . . . . . . . . . . . . . . . . . 11 5. Metadata Model Object Instances . . . . . . . . . . . . . . . 11 5.1. Use case 1: Basic Call . . . . . . . . . . . . . . . . . . 11 5.2. Use case 2: Basic Call with hold/resume . . . . . . . . . 12 5.3. Use case 3: Basic call with Transfer . . . . . . . . . . . 14 6. Security Considerations . . . . . . . . . . . . . . . . . . . 15 6.1. Connection Security . . . . . . . . . . . . . . . . . . . 15 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 8. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 16 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 9.1. Normative References . . . . . . . . . . . . . . . . . . . 16 9.2. Informative References . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 Ravindranath, et al. Expires July 24, 2011 [Page 2] Internet-Draft SIP Recording Metadata January 2011 1. Introduction Session recording is a critical requirement in many communications environments such as call centers and financial trading. In some of these environments, all calls must be recorded for regulatory, compliance, and consumer protection reasons. Recording of a session is typically performed by sending a copy of a media stream to a recording device. This document focuses on the Recording metadata which describes the communication session. The document describes a metadata model as viewed by Session Recording Server, the requirements for which are described in [I-D.ietf-siprec-req] and the architecture for which is described in [I-D.ietf-siprec-architecture]. 2. Terminology 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]. This document only uses these key words when referencing normative statements in existing RFCs." 3. Metadata Model Metadata is the data that describes the communication session. Below diagram shows a model for Metadata as viewed by Session Recording Server (SRS). Ravindranath, et al. Expires July 24, 2011 [Page 3] Internet-Draft SIP Recording Metadata January 2011 +-------------------------------+ 1 | Recording Session (RS) |---------------+ +-------------------------------+ | | 1..* | | | | 0..* | +-------------------------------+ | | Communication Session (CS) | 1 | | Group |---------------| +-------------------------------+ | | 1 | | | | 1..* | +-------------------------------+ | | Communication Session (CS) | 1 | | |---------------| +-------------------------------+ | +------------+ | 0..* |1..* | | | | | | 0..* |Application | | 2..* |0..* |-------| Data | +-------------+ receives +----------------+ | | | | Participant |----------| Media Streams | | +------------+ | |0..* 0..*| | | | | | | | | | | | | | | sends | | | | |----------| | | | |1.* 0..*| | | +-------------+ +----------------+ | | | | |1 |1 | | | | +----------------------------------------+ The mechanism MUST provide a means to convey every attribute mentioned in the metamodel. The Session Recording Client (SRC) MAY initiate the Recording Session. It should be noted that the Recording Session is a completely independent from the Communication Session that is being recorded at both the SIP dialog level and at the session level. The metadata MUST be conveyed from SRC to SRS. The metadata MAY be conveyed in Recording Session Dialog. Note that the metadata model captures changes that occur over the duration of the recording session. For example, if the call is transferred from one participant to another, then the SRC SHALL Ravindranath, et al. Expires July 24, 2011 [Page 4] Internet-Draft SIP Recording Metadata January 2011 convey a change of participant and the properties of the new media stream to the SRS. Some of the data in the model may not be conveyed explicitly from the SRC to the SRS, if it can be obtained contextually by the SRS. For instance, the timing of changes may not explicitly conveyed from the SRC to the SRC, because the mechanism (yet to be defined) which conveys the metadata may implicitly provide the timing. (E.g. the time a change occurred by be assumed to be the same as the time when notification of the change is received by the SRS.) 4. Recording Metadata elements This section describes the different elements and its attributes of the metadata model shown above. This section also describes in brief on how the different elements of metadata are associated. 4.1. Recording Session +-------------------------------+ | Recording Session (RS) | +-------------------------------+ | Recording RequestorID(SRC or | +-----------------+ | SRS) | 1 0..* | | | |------------|Application Data | | Recording Type (Selective | | | | Persistant) | +-----------------+ +-------------------------------+ | 1..* | | 0..* Communication Session Group(CS Group) A Recording Session element represents one instance of a Recording Session. 4.1.1. Attributes A Recording Session element MAY have attributes like: o Recording requestor ID(which could be SRS or SRC). o Recording type - This attribute indicates whether the recording session is selective or persistent. Ravindranath, et al. Expires July 24, 2011 [Page 5] Internet-Draft SIP Recording Metadata January 2011 4.1.2. Associations One instance of Recording Session SHALL have: o Zero or more instances of Communication Session Group.This is to accommodate persistent recording cases. o Each CS Group MUST be associated with one or more Recording Sessions [ setup by the same SRC.] 4.2. Communication Session Group Recording Session (RS) | 1..* | | 0..* +-------------------------------+ | Communication Session | | Group | +-------------------------------+ | Unique-ID | +----------------+ | | 1 0..* | | | |-----------|Application Data| | | | | +-------------------------------+ +----------------+ | 1 | | 1..* Communication Session (CS) A Communication Session Group provides association or linking of Communication Sessions. 4.2.1. Attributes A CS Group MUST have a Unique-ID attribute. SRC (or MAY be SRS) MUST ensure the uniqueness of Unique-ID in case multiple SRC interacts with the same SRS. The mechanism by which SRC creates this unique-ID and ensures its uniqueness is outside the scope of SIPREC. NOTE: Need more clarity/use cases on how the unique-ID SHALL be used 4.2.2. Associations A communication Session Group SHALL be associated with RS and CS in the following manner: Ravindranath, et al. Expires July 24, 2011 [Page 6] Internet-Draft SIP Recording Metadata January 2011 o There can be one or more Recording Session elements per Communication Session Group. o Each Communication Session Group MUST be associated with one or more RS [ setup by the same SRC] o There MAY be one or more Communication Sessions per CS Group [e.g. Consult Transfer] o Each CS MUST be associated to one CS-Group 4.3. Communication Session Communication Session Group(CS Group) | 1 | | 1..* +-------------------------------+ +-----------------+ | Communication Session (CS) | 1 0..* | | | |---------------|Application Data | +-------------------------------+ | | | | +-----------------+ | Call Termination Reason | | Force Deletion | +-------------------------------+ | | | 0..* |1..* | | | 2..* |0..* Participant Media Stream A Communication Session block/element in the metadata model represents Communication Session and its properties needed as seen by SRC. 4.3.1. Attributes A communication Session block SHALL have the following attributes: o Call Termination Reason - This represents the reason why a CS was terminated. This MAY be derived from SIP Reason header of CS. call termination reason MUST be optional and MAY be included in metadata after the call is terminated. NOTE: Attributes like Retention (represent the value/duration for which Media streams of the CS needs to be retained), Access Information e.t.c that are primarily related to policy will not be Ravindranath, et al. Expires July 24, 2011 [Page 7] Internet-Draft SIP Recording Metadata January 2011 passed in metadata from SRC to SRS. However if there are implementations where SRC has enough information, this could be sent as App Data attached to CS 4.3.2. Associations A Communication Session SHALL be associated to CS-Group,Participant and Media Stream. Cardinalities between CS and Participant allows: o CS to have atleast two or more participants o Participant may be associated with zero or more CS's (It is possible, though unlikely, that there are participants who are not part of any CS). An example of such a case is participants in a premixed media stream. The SRC may have knowledge of such Participants, yet not have any signaling relationship with them. This might arise if one participant in CS is a conf focus. Another use case is if one UA in CS works in 3pcc mode to acquire an MoH media stream, this might be reflected as unique source for media stream without having a reported signaling relationship to it. o The model also allows participants in CS that are not participants in the media. An example is the identity of a 3pcc controller that has initiated a CS to two or more participants of the CS. Another example is the identity of a conference focus. Of course a focus is probably in the media, but since it may only be there as a mixer, it may not report itself as a participant in any of the media streams. Cardinalities between CS and Media Stream allows: o A CS to have zero or more Streams o A stream can be associated with 1 or more CS. An example is multicast MoH stream which might be associated with many CSs. Also if we were to consider a B2BUA to have a separate CS on each "side" then they might share a stream.(Though more likely this would be treated as a single CS.) 4.4. Participant Ravindranath, et al. Expires July 24, 2011 [Page 8] Internet-Draft SIP Recording Metadata January 2011 Communication Session (CS) | 0..* | | 2..* +-------------------------------+ | Participant | | | +-------------------------------+ | AoR list | +-----------------+ | Name | 1 0..* | | | Participant Type |------------|Application Data | | | | | +-------------------------------+ +-----------------+ | 0..* 1..*| receives| |sends | 0..* 0..*| Media Stream A Participant block has information about user who is part of CS. 4.4.1. Attributes Participant has attributes like: o AoR list - Has list of AoRs. An AoR MAY be SIP/SIPS/TEL URI. There MAY be cases where a participant can have more than one AoR [ e.g. P-Asserted-ID which can have both SIP and TEL URIs] o Name - This attribute represents Participant name(SIP display name) or DN number ( in case it is known) o Participant Type - This attribute can have values as "internal" or "external" or "don't know" (in cases where it is not possible to determine). OPEN ITEM: Need to conclude on what other attributes [ like Participant Role ] are needed to be represented in the model 4.4.2. Associations Cardinalities between participant and Media Stream allows: o Participant to receives zero or more media streams o Participant to send zero or more media streams. (Same participant provides multiple streams e.g. audio and video) o Media stream to be received by zero or more participants. Its possible, though perhaps unlikely, that a stream is generated but sent only to the SRC and SRS, not to any participant. E.g. In Ravindranath, et al. Expires July 24, 2011 [Page 9] Internet-Draft SIP Recording Metadata January 2011 conferencing where all participants are on hold and the SRC is collocated with the focus. Also a media stream may be received by multiple participants (e.g. Whisper calls, side conversations). o Media stream to be sent by one or more participants (pre-mixed streams). NOTE: Example of a case where a participant may receive Zero or more streams - a Supervisor may have side conversation with Agent, while Agent converses with customer. 4.5. Media Stream Participant | 0..* 1..*| receives| |sends | 0..* 0..*| +-------------------------+ | Media Stream | | | Communication 1..* 0..* +-------------------------+ Session ------------| Start Time | +--------+ | End Time |1 0..* | | | Codec params |--------|Appl | | Media Stream Reference | | Data | +-------------------------+ +--------+ A Media Stream block shall have properties of media as seen by SRC and sent to SRS. Different instances of Media Stream block would be created whenever there is a change in media (e.g. dir change like pause/resume and/or codec change and/or participant change.). 4.5.1. Attributes A Media Stream block SHALL have the following attributes: o Start Time - Represents Media Start time at SRC. o End Time - Represents Media End time at SRC. This is an optional attribute and MAY be included after a stream ends o Codec params - represents codec parameters of the CS media o Media Stream Reference - In implementations this can reference to m-line OPEN ITEM: Is it required to model media streams that are not recorded[ e.g SRC offered certain media types but SRS choose to accept only subset of them] ? Ravindranath, et al. Expires July 24, 2011 [Page 10] Internet-Draft SIP Recording Metadata January 2011 4.5.2. Associations A Media Stream SHALL be associated with Participant and CS. The details of association with the Participant are described in the Participant block section. The details of association with CS is mentioned in the CS section. 4.6. Application Data A recording metadata object MAY have a opaque application data. This opaque data is intended to be used by vendor specific applications on SRS. 5. Metadata Model Object Instances This section describes the metadata model object instances for different use cases of SIPREC. For the sake of simplicity as the media streams sent by each of the participants is received by every other participant in these use cases, it is NOT shown in the object instance diagrams below. 5.1. Use case 1: Basic Call Basic call between two Participants A and B. In this use case each participant sends one Media Stream. Ravindranath, et al. Expires July 24, 2011 [Page 11] Internet-Draft SIP Recording Metadata January 2011 +-------------------------------+ | Recording Session (RS) | +-------------------------------+ | | | +-------------------------------+ | Communication Session (CS) | | Group(CSG) | +-------------------------------+ | Unique-id1 | +-------------------------------+ | | | +----------------+ | Communication | | Session (CS) | +----------------+ | | +----------------+ | |-------------------+ | | | +---------------+ | +---------------+ | ParticipantA | | | ParticipantB | | | | | | +---------------+ | +---------------+ | | | sends | | | sends | | | +---------------+ | +---------------+ |Media Stream A1| | |Media Stream B1| +---------------+ | +---------------+ |MediaStream Ref| | |MediaStream Ref| |codec params |---+---|codec params | +---------------+ +---------------+ 5.2. Use case 2: Basic Call with hold/resume Basic call between two Participants A and B and with Participant A or B doing a Hold/Resume. In this use case each participant sends one Media Stream. After Hold/Resume the properties of Media MAY change. +-------------------------------+ Ravindranath, et al. Expires July 24, 2011 [Page 12] Internet-Draft SIP Recording Metadata January 2011 | Recording Session (RS) | +-------------------------------+ | | | +-------------------------------+ | Communication Session (CS) | | Group(CSG) | +-------------------------------+ | Unique-id1 | +-------------------------------+ | | | +----------------+ | Communication | +-| Session (CS) |----------------------------------------------+ | +----------------+ | | | | | | +----------------+ | | | | | |-------------------+ | | | | | | +---------------+ +---------------+ | | | ParticipantA | | ParticipantB |-----------+ | | | |--+ | | | | | +---------------+ | +---------------+ |sends(After | | | | | | | | Resume) | | | | | | | +--------------+ | | sends | | +--+ | sends | |MediaStream B3| | | | -----+ | | +-----+ +--------------+ | | +---------------+ | | +---------------+ | |MediaStreamRef|-| | |Media Stream A1| | | |Media Stream B1| | |Codec Params | | | +---------------+ | | +---------------+ | | | | +-|MediaStreamref | | | |MediaStreamRef | | +--------------+ | |codec params | | | |codec params |-|-------------------| +---------------+ | | +---------------+ | | | | | | +------------+ |sends |sends (hold) | | sends |(Resume) | | | (hold) +-------+ +-------+ | | | | | +---------------+ +---------------+ +--------------+ | |Media Stream A2| |Media Stream A3| |MediaStream B2| | +---------------+ +---------------+ | | | |MediaStreamref | |MediaStreamRef | +--------------+ | |codec params | |codec params | |Codec Params | | +---------------+ +---------------+ |MediaStreamRef| | Ravindranath, et al. Expires July 24, 2011 [Page 13] Internet-Draft SIP Recording Metadata January 2011 | | | | | | | +--------------+ | | | | | +------------------------------------------------------+ NOTE: Need discssions on how to represent Hold/Resume from SRC to SRS and Pause/Resume from SRS to SRC. 5.3. Use case 3: Basic call with Transfer Basic call between two Participants A and B and with Participant A transfer(consult transfer) to Participant C. In this use case each participant sends one Media Stream. After transfer the properties of Participant A Media MAY change. +-------------------------------+ | Recording Session (RS) | +-------------------------------+ | | | +-------------------------------+ | Communication Session (CS) | | Group(CSG) | +-------------------------------+ | Unique-id1 | +-------------------------------+ | |----------------- | | +----------------+ +----------------+ | Communication | | Communication | | Session (CS)1 | | Session (CS)2 | +----------------+ +----------------+-----------+ | | | | | +----------------+ +----------------+ | | | |-------------------+ | | | | | +---------------+ | +---------------+ | | ParticipantA | | | ParticipantB | | | | | | | | +---------------+ | +---------------+ | | | | | sends | | | sends | | | | | Ravindranath, et al. Expires July 24, 2011 [Page 14] Internet-Draft SIP Recording Metadata January 2011 +---------------+ | +---------------+ | |Media Stream A1| | |Media Stream B1| | +---------------+ | +---------------+ | | | | | | | |codec params | | | Media Stream | | | Media Stream |---+---| Ref | | | Ref | |codec params | | +---------------+ +---------------+ | | | +----------------------------| | | +--------------------------------+ | | | | +---------------+ +---------------+ | | Participant A | | Participant C | | | | | | | +---------------+ +---------------+ | | | | | sends (After transfer) | sends | +----------------+ +----------------+| | Media Stream A2| | Media Stream C1|| +----------------+ +----------------+| | Media StreamRef| | Media StreamRef|| | Codec params | | Codecparams || | | | || +----------------+ +----------------+| | | | | | | | | | +-------------------------------------------+ 6. Security Considerations The metadata information sent from SRC to SRS MAY reveal sensitive Information about different participants of CS. For this reason, it is RECOMMENDED that a SRC use a strong means for authentication and metadata information protection and that it apply comprehensive authorization rules when using the metadata model defined in this document. The following sections will discuss each of these aspects in more detail. 6.1. Connection Security It is RECOMMENDED that a SRC authenticate SRS using the normal SIP authentication mechanisms, such as Digest as defined in Section 22 of Ravindranath, et al. Expires July 24, 2011 [Page 15] Internet-Draft SIP Recording Metadata January 2011 [RFC3261]. The mechanism used for conveying the metadata information MUST ensure integrity and SHOULD ensure confidentially of the information. In order to achieve these, an end-to-end SIP encryption mechanism, such as S/MIME described in [RFC3261], SHOULD be used. If a strong end-to-end security means (such as above) is not available, it is RECOMMENDED that a SRC use mutual hop-by-hop Transport Layer Security (TLS) authentication and encryption mechanisms described in "SIPS URI Scheme" and "Interdomain Requests" of [RFC3261]. 7. IANA Considerations Not Applicable 8. Acknowledgement We wish to thank John Elwell, Henry Lum, Leon Portman, De Villers, Andrew Hutton, Deepanshu Gautam for their valuable comments. 9. References 9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002. 9.2. Informative References [I-D.ietf-siprec-req] Rehor, K., Portman, L., Hutton, A., and R. Jain, "Requirements for SIP-based Media Recording (SIPREC)", draft-ietf-siprec-req-06 (work in progress), December 2010. [I-D.ietf-siprec-architecture] Hutton, A., Portman, L., Jain, R., and K. Rehor, "An Architecture for Media Recording using the Session Initiation Protocol", draft-ietf-siprec-architecture-01 (work in progress), October 2010. Ravindranath, et al. Expires July 24, 2011 [Page 16] Internet-Draft SIP Recording Metadata January 2011 Authors' Addresses Ram Mohan R Cisco Systems, Inc. Cessna Business Park, Kadabeesanahalli Village, Varthur Hobli, Sarjapur-Marathahalli Outer Ring Road Bangalore, Karnataka 560103 India Email: rmohanr@cisco.com Parthasarathi R Cisco Systems, Inc. Cessna Business Park, Kadabeesanahalli Village, Varthur Hobli, Sarjapur-Marathahalli Outer Ring Road Bangalore, Karnataka 560103 India Email: partr@cisco.com P. Kyzivat Cisco Systems, Inc. 1414 Massachusetts Avenue Boxborough, MA 01719 USA Email: pkyzivat@cisco.com Ravindranath, et al. 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