SIPREC R. Ravindranath Internet-Draft Cisco Systems Intended status: Standards Track Parthasarathi. Ravindran Expires: August 2, 2016 Nokia Networks Paul. Kyzivat Huawei January 30, 2016 Session Initiation Protocol (SIP) Recording Metadata draft-ietf-siprec-metadata-19 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) and the Recording metadata format. Status of This Memo This Internet-Draft is submitted 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 August 2, 2016. Copyright Notice Copyright (c) 2016 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 Ravindranath, et al. Expires August 2, 2016 [Page 1] Internet-Draft SIP Recording Metadata January 2016 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 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. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Metadata Model . . . . . . . . . . . . . . . . . . . . . . . 4 5. Recording metadata Format . . . . . . . . . . . . . . . . . . 6 5.1. XML data format . . . . . . . . . . . . . . . . . . . . . 6 5.1.1. Namespace . . . . . . . . . . . . . . . . . . . . . . 7 5.1.2. recording . . . . . . . . . . . . . . . . . . . . . . 7 6. Recording Metadata classes . . . . . . . . . . . . . . . . . 7 6.1. Recording Session . . . . . . . . . . . . . . . . . . . . 7 6.1.1. Attributes . . . . . . . . . . . . . . . . . . . . . 8 6.1.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 8 6.2. Communication Session Group . . . . . . . . . . . . . . . 8 6.2.1. Attributes . . . . . . . . . . . . . . . . . . . . . 9 6.2.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 9 6.3. Communication Session . . . . . . . . . . . . . . . . . . 10 6.3.1. Attributes . . . . . . . . . . . . . . . . . . . . . 10 6.3.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 11 6.4. CSRSAssociation . . . . . . . . . . . . . . . . . . . . . 12 6.4.1. Attributes . . . . . . . . . . . . . . . . . . . . . 13 6.4.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 13 6.5. Participant . . . . . . . . . . . . . . . . . . . . . . . 13 6.5.1. Attributes . . . . . . . . . . . . . . . . . . . . . 14 6.5.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 14 6.6. ParticipantCSAssociation . . . . . . . . . . . . . . . . 15 6.6.1. Attributes . . . . . . . . . . . . . . . . . . . . . 15 6.6.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 16 6.7. Media Stream . . . . . . . . . . . . . . . . . . . . . . 16 6.7.1. Attributes . . . . . . . . . . . . . . . . . . . . . 17 6.7.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 17 6.8. ParticipantStream Association . . . . . . . . . . . . . . 17 6.8.1. Attributes . . . . . . . . . . . . . . . . . . . . . 18 6.8.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 19 6.9. associate-time/disassociate-time . . . . . . . . . . . . 19 6.10. Unique ID format . . . . . . . . . . . . . . . . . . . . 19 6.11. Metadata version Indicator . . . . . . . . . . . . . . . 19 7. Recording metadata snapshot Request format . . . . . . . . . 20 8. SIP Recording Metadata Example . . . . . . . . . . . . . . . 20 8.1. Complete SIP Recording Metadata Example . . . . . . . . . 20 Ravindranath, et al. Expires August 2, 2016 [Page 2] Internet-Draft SIP Recording Metadata January 2016 8.2. Partial Update of Recording metadata XML body . . . . . . 22 9. XML Schema definition for Recording metadata . . . . . . . . 23 10. Security Considerations . . . . . . . . . . . . . . . . . . . 27 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28 11.1. SIP recording metadata Schema Registration . . . . . . . 28 12. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 28 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 28 13.1. Normative References . . . . . . . . . . . . . . . . . . 28 13.2. Informative References . . . . . . . . . . . . . . . . . 30 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30 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(SRS) and the Recording metadata format, the requirements for which are described in [RFC6341] and the architecture for which is described in [RFC7245]. 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. Definitions Metadata Model: An abstract representation of metadata using a Unified Modelling Language(UML) class diagram. Metadata classes: Each block in the model represents a class. A class is a construct that is used as a blueprint to create instances(called objects) of itself. The description of each class also has representation of its attributes in a second compartment below the class name. Attributes: Attributes represent the elements listed in each of the classes. The attributes of a class are listed in the second compartment below the class name. Each instance of class conveys values for these attributes which adds to the recording's metadata. Ravindranath, et al. Expires August 2, 2016 [Page 3] Internet-Draft SIP Recording Metadata January 2016 Linkages: Linkages represent the relationship between the classes in the model. Each represents a logical connection between classes(or objects) in class diagrams(or object diagrams). The linkages used in the metadata model of this document are associations. This document also refers to the terminlogy defined in [RFC6341]. 4. Metadata Model Metadata is the information that describes recorded media and the Communication Session(CS) to which they relate. The diagram below shows a model for metadata as viewed by a SRS. Ravindranath, et al. Expires August 2, 2016 [Page 4] Internet-Draft SIP Recording Metadata January 2016 +-------------------------------+ | Recording Session (RS) | +-------------------------------+ |1..* | 1..* | | | | 0..* | +-----------------+ +------------+ | | Communication | | CSRS | | | Session (CS) | | Association|--+ | Group | | | | +-----------------+ +------------+ | | 0..1 | | |0..* | 1..* +-------------------------------+ | Communication Session (CS) | | | +-------------------------------+ | 1..* |0..1 +-----+ | | | 0..* |0..* | +-------------+ receives +----------------+ | | Participant |----------| Media Streams | | | |0..* 0..*| | | | | | | | | | | | | | | sends | | | | |----------| | | | |1.* 0..*| | | +-------------+ +----------------+ | | | | | | | +------------------------+------------+ | | | | | +------------------+ +----------------------+ | |ParticipantCS | | ParticipantStream | +-----------| Association | | Association | | | | | +------------------+ +----------------------+ The metadata model is a class diagram in Unified Modelling Language(UML). The model describes the structure of metadata in general by showing the classes, their attributes, and the relationships among the classes. Each block in the model above represents a class. The linkages between the classes represent the Ravindranath, et al. Expires August 2, 2016 [Page 5] Internet-Draft SIP Recording Metadata January 2016 relationships which can be associations or composition. The metadata is conveyed from SRC to SRS. The model allows the capture of a snapshot of a recording's metadata at a given instant in time. Metadata changes to reflect changes in what is being recorded. For example, if a participant joins a conference, then the SRC sends the SRS a snapshot of metadata having that participant information (with attributes like name/AoR pair and associate-time.) Some of the metadata is not required to be conveyed explicitly from the SRC to the SRS, if it can be obtained contextually by the SRS(e.g., from SIP or SDP signalling). 5. Recording metadata Format This section gives an overview of the Recording metadata format. Some data from the metadata model is assumed to be made available to the SRS through Session Description Protocol (SDP)[RFC4566], and therefore this data is not represented in the XML document format specified in this document. SDP attributes describe different media formats like audio, video. The other metadata attributes, such as participant details, are represented in a new Recording specific XML document of type 'application/rs-metadata+xml'. The SDP label attribute [RFC4574] provides an identifier by which a metadata XML document can refer to a specific media description in the SDP sent from the SRC to the SRS. The XML document format can be used to represent either the complete metadata or a partial update to the metadata. The latter includes only elements that have changed compared to the previously reported metadata. 5.1. XML data format Every recording metadata XML document MUST contain a element. The element acts as a container for all other elements in this XML document. A recording object is an XML document. It MUST have the XML declaration and it SHOULD contain an encoding declaration in the XML declaration, e.g., "". If the charset parameter of the MIME content type declaration is present and it is different from the encoding declaration, the charset parameter takes precedence. Every application conforming to this specification MUST accept the UTF-8 character encoding to ensure the minimal interoperability. Ravindranath, et al. Expires August 2, 2016 [Page 6] Internet-Draft SIP Recording Metadata January 2016 Syntax and semantic errors in an XML document should be reported to the originator using application specific mechanisms. 5.1.1. Namespace The namespace URI for elements defined by this specification is a Uniform Resource Namespace (URN) [RFC2141], using the namespace identifier 'ietf' defined by [RFC2648] and extended by [RFC3688]. The URN is: urn:ietf:params:xml:ns:recording:1 5.1.2. recording The element MUST contain an xmlns namespace attribute with value as urn:ietf:params:xml:ns:recording:1. One recording element MUST be present in every recording metadata XML document. A recording element MAY contain a element indicating whether the XML document is a complete document or a partial update. If no element is present then the default value is "complete". 6. Recording Metadata classes This section describes each class of the metadata model, and the attributes of each class. This section also describes how different classes are linked and the XML element for each of them. 6.1. Recording Session +-------------------------------+ | Recording Session (RS) | +-------------------------------+ | | | start-time | | end-time | | | | | +-------------------------------+ |1..* | 1..* | | |0..* | 0..* Communication Communication Session Session Group(CS Group) Ravindranath, et al. Expires August 2, 2016 [Page 7] Internet-Draft SIP Recording Metadata January 2016 Each instance of a Recording Session(RS) class namely the Recording Session Object represents a SIP session created between an SRC and SRS for the purpose of recording a Communication Session. RS object is represented in XML schema using element. That in turn relies on the SIP/SDP session with which the XML document is associated to provide the attributes of the RS element. 6.1.1. Attributes A RS class has the following attributes: o start-time - Represents the start time of a Recording Session object. o end-time - Represents the end time of a Recording Session object. start-time and end-time attribute values are derivable from Date header(if present in SIP message) in RS. In cases where Date header is not present, start-time is derivable from the time at which SRS receives the notification of SIP message to setup RS and and end-time is derivable from the time at which SRS receives disconnect on the RS SIP dialog. 6.1.2. Linkages Each instance of RS has: o Zero or more instances of Communication Session Group (CSG). o Zero or more instances of Communication Session(CS) objects. CSs and CSGs are optional to accommodate persistent recording, where there may sometimes be none. 6.2. Communication Session Group Ravindranath, et al. Expires August 2, 2016 [Page 8] Internet-Draft SIP Recording Metadata January 2016 Recording Session (RS) | 1..* | | 0..* +-------------------------------+ | Communication Session | | Group | +-------------------------------+ | group_id | | associate-time | | disassociate-time | | | +-------------------------------+ | 0..1 | | 1..* Communication Session (CS) One instance of a Communication Session Group(CS-Group) class namely the Communication Session Group object provides association or linking of Communication Sessions. CS-Group object is represented in XML schema using element. 6.2.1. Attributes A CS-Group has the following attributes: o group_id - This is to group different CSs that are related. SRC (or SRS) is responsible for ensuring the uniqueness of group_id in case multiple SRC interacts with the same SRS. The mechanism by which SRC groups the CS is outside the scope of SIPREC. o associate-time - This is the time when a grouping is formed. The rules that determine how a grouping of different CS objects is done by SRC is outside the scope of SIPREC. o disassociate-time - disassociate-time for CS-Group is calculated by SRC as the time when the grouping ends. 6.2.2. Linkages The linkages between CS-Group class and other classes are associations. A CS-Group is associated with RS and CS in the following manner: o There are one or more RS objects per CS-Group. Ravindranath, et al. Expires August 2, 2016 [Page 9] Internet-Draft SIP Recording Metadata January 2016 o Each CS-Group object has to be associated with one or more RS. Here each RS can be setup by the potentially different SRCs. o There are one or more CSs per CS-Group (for example, in case where the call is transferred). 6.3. Communication Session Recording Communication Session Session Group(CS Group) |1..* | 0..1 | | |0..* | 1..* +-------------------------------+ | Communication Session (CS) | +-------------------------------+ | session_id | | sipSessionID | | reason | | group-ref | | start-time | | stop-time | +-------------------------------+ | | | 0..* |0..1 | | | 0..* |0..* Participant Media Stream A Communication Session(CS) class and its object in the metadata model represents a Communication Session and its properties needed as seen by SRC. CS object is represented in XML schema using element. 6.3.1. Attributes A CS class has the following attributes: o session_id - This attribute is used to uniquely identify an instance of CS object namely the session XML element with in the metadata XML document. session_id is generated using the rules mentioned in Section 6.10. Ravindranath, et al. Expires August 2, 2016 [Page 10] Internet-Draft SIP Recording Metadata January 2016 o reason - This represents the reason why a CS was terminated. The value for this attribute is derived from SIP Reason header [RFC3326] of CS. There MAY be multiple instances of the reason XML element inside a session element. The reason XML element has 'protocol' as an attribute, which indicates the protocol from which the reason string is derived. The default value for protocol attribute is "SIP". The reason element can be derived from a SIP Reason header in the CS. o sipSessionID - This attribute carries sip Session-ID defined in [I-D.ietf-insipid-session-id]. Each CS object can have zero or more sipSessionID elements. More than one sipSessionID may be present in a CS for Conference flows. For example, if three participants A, B and C are in a conference that has a focus acting as SRC, the metadata sent from the SRC to the SRS will likely have three sipSessionID elements that correspond to the SIP dialogs the focus has with each of the three participants. o group-ref - A group-ref attribute MAY be present to indicate the group to which the enclosing session belongs. o start-time - This optional attribute represents start time of CS as seen by SRC. o Stop-time - This optional attribute represents stop time of CS as seen by SRC. This document does not specify attributes relating to what should happen to a recording of a CS after it has been delivered to the SRS (E.g., how long to retain the recording, what access controls to apply.) The SRS is assumed to behave in accordance with its local policy. The ability for the SRC to influence this policy is outside the scope of this document. However if there are implementations where SRC desires to specify its own policy preferences, this could be sent as extension data attached to the CS. 6.3.2. Linkages A CS is linked to CS-Group, Participant, Media Stream and RS classes using the association relationship. Association between CS and Participant allows: o CS to have zero or more participants o Participant is associated with zero or more CSs. This includes participants who are not directly 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 Ravindranath, et al. Expires August 2, 2016 [Page 11] Internet-Draft SIP Recording Metadata January 2016 signaling relationship with them. This might arise if one participant in CS is a conference focus. To summarize, even if the SRC does not have direct signalling relationships with all participants in a CS, it should nevertheless create a participant object for each participant that it knows about. o The model also allows participants in CS that are not participants in the media. An example is the identity of a Third Party Call Control(3pcc) 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. Association between CS and Media Stream allows: o A CS to have zero or more streams o A stream can be associated with at most one CS. A stream in a persistent RS is not required to be associated with any CS before the CS is created and hence the zero associationa is allowed. Association between CS and RS allows: o Each instance of RS has Zero or more instances of CS objects. o Each CS has to be associated with one more RS. Each RS can be potentially setup by different SRCs. 6.4. CSRSAssociation 1..* 0..* Recording Communication Session ----------+---------- Session | | | +-----------------------+ | CSRSAssociation | | | +-----------------------+ | association-time | | disassociaton-time | | session_id | +-----------------------+ Ravindranath, et al. Expires August 2, 2016 [Page 12] Internet-Draft SIP Recording Metadata January 2016 The CSRSAssociation class describes the association of a CS to an RS for a period of time. A single CS may be associated with different RSs (perhaps by different SRCs) and may be associated and dissociated several times. The CSRSAssociation is represented in XML using sessionrecordingassoc XML element. 6.4.1. Attributes CSRSAssociation class has the following attributes: o associate-time - associate-time is calculated by SRC as the time it sees a CS is associated to a RS o disassociate-time- disassociate-time is calculated by SRC as the time it see a CS disassociate from a RS. o session_id - Each instance of this class MUST have session_id attribute that identifies the the CS to which this association belongs to. 6.4.2. Linkages CSRSAssociation class is linked to CS and RS classes. 6.5. Participant Communication Session (CS) | 0..* | | 0..* +-------------------------------+ | Participant | +-------------------------------+ | nameID | | participant_id | | | +-------------------------------+ | 0..* 1..*| receives| |sends | 0..* 0..*| Media Stream Ravindranath, et al. Expires August 2, 2016 [Page 13] Internet-Draft SIP Recording Metadata January 2016 A Participant class and its objects has information about a device that is part of a CS and/or contributes/consumes media stream(s) belonging to a CS. Participant object is represented in XML schema using element. 6.5.1. Attributes Participant has a single defined attribute: o nameID - This attribute is a list of Name/AoR tuples. An AoR can be one of SIP/SIPS/TEL URI, FQDN or IP address. The AoR MAY be drawn from From header or P-Asserted-Identity header or Remote- Party-ID header. SRCs local policy MAY also be used to decide on where to draw the AoR from. Name represents participant name(SIP display name) or dialed number (DN) (when known). Multiple tuples are allowed for cases where a participant has more than one AoR. (For example a P-Asserted-identity header [RFC3325] can have both SIP and TEL URIs.) o participant_id - This attribute is used to identify the participant XML element with in the XML document. It is generated using the rules mentioned in Section 6.10. This attribute MUST be used for all references to a participant within a CSG, and MAY be used to reference the same participant more globally. This document does not specify other attributes relating to participant e.g. participant role, participant type. An SRC which has information of these attributes can indicate the same as part of extension data to participant from SRC to SRS. 6.5.2. Linkages The participant class is linked to MediaStream (MS) and CS class using association relationship. The association between participant and MS allows: o participant to receive 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 conferencing where all participants are on hold and the SRC is Ravindranath, et al. Expires August 2, 2016 [Page 14] Internet-Draft SIP Recording Metadata January 2016 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). Example of a case where a participant receives zero or more streams - a supervisor may have side conversation with agent, while agent converses with customer. 6.6. ParticipantCSAssociation 1..* 0..* Communication Session ----------+---------- Participant | | | +-------------------------+ | ParticipantCSAssociation| | | | | +-------------------------+ | associateTime | | disassociateTime | | param | | participant_id | | session_id | +-------------------------+ The ParticipantCSAssociation class describes the association of a participant to an CS for a period of time. A participant may be associated and dissociated from a CS several times. (For example, connecting to a conference, then disconnecting, then connecting again.) ParticipantCSAssociation object is represented in XML schema using element. 6.6.1. Attributes ParticipantCS association class has the following attributes: o associate-time - associate-time is calculated by SRC as the time it sees a participant is associated to CS Ravindranath, et al. Expires August 2, 2016 [Page 15] Internet-Draft SIP Recording Metadata January 2016 o disassociate-time- disassociate-time is calculated by the SRC as the time it sees a participant disassociate from a CS. It is possible that a given participant can have multiple associate/ disassociate times within given communication session. o param - An optional attribute describing the capabilities of a participant in a CS, as defined in [RFC3840]. The capablities are represented using param XML element in the metadata. The 'param' XML element encoding defined in [RFC4235] is used to represent the capabilties attributes in metadata. Each participant may have zero or more capabilities. A participant may use different capabilities depending on the role it plays at a particular instance. For example if a participant moves across different CSs (e.g., due to transfer) or is simultaneously present in different CSs with different roles. o participant_id - This attribute identifies the participant to which this association belongs to. o session_id - This attribute identifies the session to which this association belongs to. 6.6.2. Linkages The participantCSAssociation class is linked to participant and CS classes. 6.7. Media Stream Participant | 0..* 1..*| receives| |sends | 0..* 0..*| +-------------------------+ | Media Stream | Communication 0..1 0..* +-------------------------+ Session ------------| | | label | | content-type | | stream_id | | session_id | +-------------------------+ A MS class (and its objects) has the properties of media as seen by SRC and sent to SRS. Different snapshots of a media stream object Ravindranath, et al. Expires August 2, 2016 [Page 16] Internet-Draft SIP Recording Metadata January 2016 may be sent whenever there is a change in media (e.g. direction change like pause/resume and/or codec change and/or participant change.). MS object is represented in XML schema using element. 6.7.1. Attributes A MS class has the the following attributes: o label - The label attribute within the stream XML element references an SDP "a=label" attribute that identifies an m-line within the RS SDP. That m-line carries the media stream from the SRC to the SRS. o content-type - The content of an MS element will be described in terms of value from the [RFC4796] registry. If the SRC wishes to convey the Content-type to the SRS, it does so by including an 'a=content' attribute with the m-line in the RS SDP. o stream_id - Each stream element has unique 'stream_id' attribute which helps to uniquely identify stream. This identifier is generated using the rules mentioned in Section 6.10. o session_id - This attribute associates the stream with a specific session element. The metadata model should include media streams that are not being delivered to the SRS. Examples include cases where SRC offered certain media types but SRS chooses to accept only a subset of them OR an SRC may not even offer a certain media type due it its restrictions to record 6.7.2. Linkages A MS class is linked to participant and CS classes using the association relationship. The details of association with the Participant are described in the Participant class section. The details of association with CS is mentioned in the CS section. 6.8. ParticipantStream Association Ravindranath, et al. Expires August 2, 2016 [Page 17] Internet-Draft SIP Recording Metadata January 2016 +-------------------------+ | ParticipantStream | | Association | +-------------------------+ +----------Participant | association-time | | 0..*| 1..*| | disassociaton-time |---+ recv| |sends | send | | 0..*| 0..*| | recv | | | | | participant_id | | | | +-------------------------+ | | | +----------Media Stream A ParticipantStream association class describes the association of a Participant to a Media Stream for a period of time, as a sender or as a receiver, or both. This class is represented in XML using element. 6.8.1. Attributes A ParticipantStream association class has the following attributes: o associate-time: This attribute indicates the time a participant started contributing to a Media Stream o disassociate-time: This attribute indicates the time a participant stopped contributing to a Media Stream o send: This attribute indicates whether a participant is contributing to a stream or not. This attribute has a value which points to stream represented by its unique_id. The presence of this attribute indicates that a participant is contributing to a stream represented by the Unique_id. If due to changes in CS if a participant stops contributing to a stream, a snapshot MUST be sent from SRC to SRS with no Send element for that stream. o recv: This attribute indicates whether a participant is receiving a media stream or not. This attribute has a value which points to a stream represented by its Unique_id. The presence of this attribute indicates that a participant is receiving a stream represented by the Unique_id. If due to changes in CS(like hold) the participants stops receiving a stream, a snapshot MUST be sent from SRC to SRS with no Recv element for that stream. Ravindranath, et al. Expires August 2, 2016 [Page 18] Internet-Draft SIP Recording Metadata January 2016 o participant_id - This attributes points to the participant to which this streams are associated with. This XML element is used to represent a snapshot of a participant association with a stream. The send and recv XML elements MUST be used to indicate whether a participant is contributing to a stream or receiving a stream. There MAY be multiple instances of the send and recv XML elements inside a particpantstreamassoc element. If a metadata snapshot is sent with a participantstreamassoc that does not have any send and recv elements, it means that participant is neither contributing to any streams nor receiving any streams. 6.8.2. Linkages The participantStream association class is linked to participant and Stream classes. 6.9. associate-time/disassociate-time The XML and elements contain strings indicating the date and time of the status change of this tuple. The value of these elements MUST follow the IMPP datetime format [RFC3339]. Timestamps that contain 'T' or 'Z' MUST use the capitalized forms. At a time, any of the time tuple associate-time or disassociate-time MAY exist in the element namely group, session, participant and not both timestamp at the same time. As a security measure, the timestamp element SHOULD be included in all tuples unless the exact time of the status change cannot be determined. 6.10. Unique ID format A Unique id is generated in two steps: o the UUID is created using [RFC4122] o the UUID is encoded using base64 as defined in [RFC4648] The above mentioned unique-id mechanism SHOULD be used for each metadata element. Multiple SRCs can refer to the same element/UUID (how each SRC learns the UUID here is out of scope of SIPREC) 6.11. Metadata version Indicator This section defines a version indicator for metadata XML. Ravindranath, et al. Expires August 2, 2016 [Page 19] Internet-Draft SIP Recording Metadata January 2016 This version value allows the SRS to know the exact metadata XML schema used by the SRC. This document describes version 1. Implementations may not interoperate if the version implemented by the sender is not known by the receiver. No negotiation of versions is provided. There is no significance to the version number although documents which update or obsolete this document (possibly including drafts of such documents) should include a higher version number if the metadata XML schema changes. 7. Recording metadata snapshot Request format This section gives an details of metadata snapshot request format. When SRS wishes to request metadata snapshot from SRC it MUST follow the syntax described in this section. The SRS requests metadata snapshot in a request message and SHOULD insert a XML document having the namespace urn:ietf:params:xml:ns:recording:1. The Request can have the following elements. A XML element MUST be present as the top level element in the XML document. A XML element that indicates the reason for requesting snapshot as a string MAY be present as a child XML element of . 8. SIP Recording Metadata Example 8.1. Complete SIP Recording Metadata Example The following example provides all the tuples involved in Recording Metadata XML body. complete 2010-12-16T23:41:07Z sip:alice@atlanta.com FOO! bar ab30317f1a784dc48ff824d0d3715d86; remote=47755a9de7794ba387653f2099600ef2 Ravindranath, et al. Expires August 2, 2016 [Page 20] Internet-Draft SIP Recording Metadata January 2016 7+OTCyoxTmqmqyA/1weDAg== FOO! bar Bob B FOO! bar Paul FOO! bar 2010-12-16T23:41:07Z Ravindranath, et al. Expires August 2, 2016 [Page 21] Internet-Draft SIP Recording Metadata January 2016 2010-12-16T23:41:07Z 2010-12-16T23:41:07Z i1Pz3to5hGk8fuXl+PbwCw== UAAMm5GRQKSCMVvLyl4rFw== 8zc6e0lYTlWIINA6GR+3ag== EiXGlc+4TruqqoDaNE76ag== 8zc6e0lYTlWIINA6GR+3ag== EiXGlc+4TruqqoDaNE76ag== UAAMm5GRQKSCMVvLyl4rFw== i1Pz3to5hGk8fuXl+PbwCw== SIP Recording Metadata Example XML body 8.2. Partial Update of Recording metadata XML body The following example provides partial update in Recording metadata XML body for the above example. The example has a snapshot that carries the disassociate-time for a participant from a session. Ravindranath, et al. Expires August 2, 2016 [Page 22] Internet-Draft SIP Recording Metadata January 2016 partial Bob R FOO! bar 2010-12-16T23:41:07Z Partial update of SIP Recording Example XML body 9. XML Schema definition for Recording metadata This section defines XML schema for Recording metadata document Ravindranath, et al. Expires August 2, 2016 [Page 24] Internet-Draft SIP Recording Metadata January 2016 Ravindranath, et al. Expires August 2, 2016 [Page 25] Internet-Draft SIP Recording Metadata January 2016 Ravindranath, et al. Expires August 2, 2016 [Page 26] Internet-Draft SIP Recording Metadata January 2016 10. Security Considerations This document describes an extensive set of metadata that may be recorded by the SRS. Most of the metadata could be considered private data. 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 format defined in this document. It is RECOMMENDED that a SRC authenticate the SRS using the normal SIP authentication mechanisms, such as Digest as defined in Section 22 of [RFC3261]. The mechanism used for conveying the metadata information MUST ensure integrity and 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]. Some implementations may have the SRC choose parts of metadata that can be sent to the SRS. In other cases, SRCs may send metadata that Ravindranath, et al. Expires August 2, 2016 [Page 27] Internet-Draft SIP Recording Metadata January 2016 is not appropriate for the SRS to record. Which metadata is actually recorded by the SRS must be carefully considered to balance privacy concerns with usability. Implementations MUST control what metadata is recorded, and MUST NOT save metadata sent by the SRC that does not conform to the recording policy of the SRS. Metadata in storage needs to be provided with a level of security that is comparable to that of the recording session. 11. IANA Considerations This specification registers a new XML namespace, and a new XML schema. 11.1. SIP recording metadata Schema Registration URI: urn:ietf:params:xml:ns:recording:1 Registrant Contact: IETF SIPREC working group, Ram mohan R(rmohanr@cisco.com) XML: the XML schema to be registered is contained in Section 8. Its first line is and its last line is 12. Acknowledgement Thanks to John Elwell, Henry Lum, Leon Portman, De Villers, Andrew Hutton, Deepanshu Gautam,Charles Eckel, Muthu Arul Mozhi, Michael Benenson, Hadriel Kaplan, Brian Rosen, Scott Orton, Ofir Roth, Mary Barnes, Ken Rehor, Gonzalo Salgueiro, Yaron Pdut and Alissa Cooper for their valuable comments and inputs. Thanks to Joe Hildebrand, Peter Saint-Andre, Matt Miller for helping in writing the XML schema and Martin Thompson for validating the XML schema and providing comments on the same. 13. References 13.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC2141] Moats, R., "URN Syntax", RFC 2141, DOI 10.17487/RFC2141, May 1997, . Ravindranath, et al. Expires August 2, 2016 [Page 28] Internet-Draft SIP Recording Metadata January 2016 [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, DOI 10.17487/RFC3261, June 2002, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet: Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002, . [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session Description Protocol", RFC 4566, DOI 10.17487/RFC4566, July 2006, . [RFC4574] Levin, O. and G. Camarillo, "The Session Description Protocol (SDP) Label Attribute", RFC 4574, DOI 10.17487/RFC4574, August 2006, . [RFC4796] Hautakorpi, J. and G. Camarillo, "The Session Description Protocol (SDP) Content Attribute", RFC 4796, DOI 10.17487/RFC4796, February 2007, . [RFC3840] Rosenberg, J., Schulzrinne, H., and P. Kyzivat, "Indicating User Agent Capabilities in the Session Initiation Protocol (SIP)", RFC 3840, DOI 10.17487/RFC3840, August 2004, . [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally Unique IDentifier (UUID) URN Namespace", RFC 4122, DOI 10.17487/RFC4122, July 2005, . [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006, . [I-D.ietf-insipid-session-id] Jones, P., Salgueiro, G., and C. Pearce, "End-to-End Session Identification in IP-Based Multimedia Communication Networks", draft-ietf-insipid-session-id-16 (work in progress), October 2015. Ravindranath, et al. Expires August 2, 2016 [Page 29] Internet-Draft SIP Recording Metadata January 2016 13.2. Informative References [RFC6341] Rehor, K., Ed., Portman, L., Ed., Hutton, A., and R. Jain, "Use Cases and Requirements for SIP-Based Media Recording (SIPREC)", RFC 6341, DOI 10.17487/RFC6341, August 2011, . [RFC7245] Hutton, A., Ed., Portman, L., Ed., Jain, R., and K. Rehor, "An Architecture for Media Recording Using the Session Initiation Protocol", RFC 7245, DOI 10.17487/RFC7245, May 2014, . [RFC2648] Moats, R., "A URN Namespace for IETF Documents", RFC 2648, DOI 10.17487/RFC2648, August 1999, . [RFC3326] Schulzrinne, H., Oran, D., and G. Camarillo, "The Reason Header Field for the Session Initiation Protocol (SIP)", RFC 3326, DOI 10.17487/RFC3326, December 2002, . [RFC3325] Jennings, C., Peterson, J., and M. Watson, "Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted Networks", RFC 3325, DOI 10.17487/RFC3325, November 2002, . [RFC4235] Rosenberg, J., Schulzrinne, H., and R. Mahy, Ed., "An INVITE-Initiated Dialog Event Package for the Session Initiation Protocol (SIP)", RFC 4235, DOI 10.17487/RFC4235, November 2005, . Authors' Addresses Ram Mohan Ravindranath Cisco Systems Cessna Business Park Bangalore, Karnataka India Email: rmohanr@cisco.com Ravindranath, et al. Expires August 2, 2016 [Page 30] Internet-Draft SIP Recording Metadata January 2016 Parthasarathi Ravindran Nokia Networks Bangalore, Karnataka India Email: partha@parthasarathi.co.in Paul Kyzivat Huawei Hudson, MA USA Email: pkyzivat@alum.mit.edu Ravindranath, et al. Expires August 2, 2016 [Page 31]