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Session recording is a critical requirement in many business communications environments such as call centers and financial trading floors. In some of these environments, all calls must be recorded for regulatory and compliance reasons. In others, calls may be recorded for quality control or business analytics.
Recording is typically done by sending a copy of the session media to the recording devices. This document specifies requirements for extensions to SIP that will manage delivery of RTP media from an end-point that originates media (or that has access to it) to a recording device. This is being referred to as SIP-based Media Recording.
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 October 31, 2010.
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1.
Requirements notation
2.
Introduction
3.
Definitions
4.
Example Deployment Architectures
5.
Use Cases
6.
Requirements
7.
Security Considerations
8.
IANA Considerations
9.
Acknowledgements
10.
Contributors
11.
Normative References
§
Authors' Addresses
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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] and indicate requirement levels for compliant mechanisms.
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Session recording is a critical operational requirement in many businesses, especially where voice is used as a medium for commerce and customer support. A prime example where voice is used for trade is the financial industry. The call recording requirements in this industry are quite stringent. The recorded calls are used for dispute resolution and compliance. Other businesses such as customer support call centers typically employ call recording for quality control or business analytics, with different requirements.
Depending on the country and its regulatory requirements, financial trading floors typically must record all calls. The recorded media content must be an exact copy of the actual conversation (i.e. clipping and loss of media are unacceptable). A new call attempt would be automatically rejected if the recording device becomes temporarily unavailable. An existing call would be dropped in the same situation. In contrast, support call centers typically only record a subset of the calls, and calls must not fail regardless of the availability of the recording device.
Furthermore, the scale and cost burdens vary widely, in all markets, where the different needs for solution capabilities such as media injection, transcoding, and security-related needs do not conform well to a one-size-fits-all model. If a standardized solution supports all of the requirements from every recording market, but doing so would be expensive for markets with lesser needs, then proprietary solutions for those markets will continue to propagate. Care must be taken, therefore, to make a standards-based solution support optionality and flexibility.
It should be noted that the requirements for the protocol between a Recording Server and Recording Client have very similar requirements (such as codec and transport negotiation, encryption key interchange, firewall traversal) as compared to regular SIP media sessions. The choice of SIP for session recording provides reuse of an existing protocol. This document specifies requirements for using SIP [RFC3261] (Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, “SIP: Session Initiation Protocol,” June 2002.) to record a media session between a Recording Client and a Recording Server, The Recording Client is the source of the recorded media. The Recording Server is the sink of recorded media.
The recorded sessions can be any SIP-based RTP media sessions including voice, video, and text (as defined by [RFC4103]).
An archived session recording is typically comprised of the session media content and the session metadata. The session metadata allows recording archives to be searched and filtered at a later time. The conveyance of session metadata from the Recording Client to the Recording Server may or may not be over SIP. The requirements for session metadata delivery will be specified in a future revision of this document or in a separate document.
In some situations it may be advantageous to correlate the Communication Session with other information, such as an IM or other text chat session.
This document only considers active recording, where the Recording Client purposefully streams media to a Recording Server. Passive recording, where a recording device detects media directly from the network, is outside the scope of this document. In addition, lawful intercept is outside the scope of this document.
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Recording Server (RS): A Recording Server (RS) is a SIP User Agent (UA) that is a specialized media server or collector that acts as the sink of the recorded media. An RS is a logical function that typically archives media for extended durations of time and provides interfaces for search and retrieval of the archived media. An RS is typically implemented as a multi-port device that is capable of receiving media from several sources simultaneously. An RS is typically also the sink of the recorded session metadata. Note that the term "Server" does not imply the RS is the server side of a signaling protocol - the RS may be the initiator of recording requests, for example.
Recording Client (RC): A Recording Client (RC) is a SIP User Agent (UA) that acts as the source of the recorded media, sending it to the RS. An RC is a logical function. Its capabilities may be implemented across one or more physical devices. In practice, an RC could be a personal device (such as a SIP phone), a SIP Media Gateway (MG), a Session Border Controller (SBC) or a SIP Media Server (MS) integrated with an Application Server (AS). This specification defines the term RC such that all such SIP entities can be generically addressed under one definition. The RC itself or another entity working on its behalf (such as a SIP Application Server) may act as the source of the recording metadata.
Communication Session (CS): A session created between two or more SIP User Agents (UAs) that is the target for recording.
Recording Session (RS): The SIP session created between an RC and RS for the purpose of recording a Communication Session.
+---------------------------------------------------------------+
| (Recording Client) |
| +-------------+ +-----------+ |
| | | Communication Session | | |
| | A |<------------------------->| B | |
| | | | | |
| +-------------+ +-----------+ |
+---------------------------------------------------------------+
|
| Recording
| Session
|
v
+-------------+
| |
| Recording |
| Server |
| |
+-------------+
| Figure 1 |
Metadata: Data that describes the Communication Session.
SIPREC: The set of SIP extensions that supports recording of Communication Sessions.
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A recording system deployment consists of the Recording Client and Recording Server. Recording Control is bi-directional; Recording Media and Call Metadata are sent from the RC to RS.
+-------------+ +--------------+ | | Call Metadata | | | |-------------------------->| | | Recording | | Recording | | Client | Recording Control | Server | | (RC) |<------------------------->| (RS) | | | | | | | Recorded Media | | | |-------------------------->| | | | | | +-------------+ +--------------+
| Figure 2 |
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Use Case 1: Full-time Recording: One (or more, in the case of redundant recording) Recording Session for each Communication Session.
For example, the diagram below shows the lifecycle of Communication Sessions (CS) and the relationship to the Recording Sessions (RS)
CS |--- CS 1 ---| |--- CS 2 ---| |--- CS 3 ---| RS |--- RS 1 ---| |--- RS 2 ---| |--- RS 3 ---|
| Figure 3 |
Record every call for specific extension/person. One Recording Session is created per Communication Session.
The need to record all calls is typically due to business process purposes (such as transaction confirmation or dispute resolution) or to ensure compliance with governmental regulations. Applications include enterprise, contact center, and financial trading floors.
Also commonly known as Total Recording.
Use Case 2: Selective Recording: Start a Recording Session when a Communication Session is established. Only specific calls are recorded, possibly based on business rules. A Communication Session may or may not have a Recording Session (record only specific calls).
In this example, Communication Sessions 1 and 3 are recorded but CS 2 is not.
CS |--- CS 1 ---| |--- CS 2 ---| |--- CS 3 ---| RS |--- RS 1----| |--- RS 2 ---|
| Figure 4 |
Use Case 3: Dynamic Recording: Start/Stop a Recording Session during a Communication Session.
The Recording Session starts during a Communication Session, either manually via a user-controlled mechanism (e.g. button on user’s phone) or automatically via an application (e.g. a Contact Center customer service application) or business event. A Recording Session either ends during the Communication Session, or when the Communication Session ends.
One or more Recording Sessions per Communication Session:
CS |------------- Communication Session -----------| RS |---- RS 1 ----| |---- RS 2 -----|
| Figure 5 |
Also known as Mid-session or Mid-call Recording.
Applications include:
o Enterprise back office recording where only specific calls (based on privacy) have to be recorded
o A user requests session recording at call setup time or during a call.
Use Case 4: Persistent Recording: A Recording Session captures one or more Communication Sessions.
|--- CS 1 ---| |--- CS 2 ---| |--- CS 3 ---| RS |---------------------- Recording Session ---------------------|
| Figure 6 |
A Recording Session records continuously without interruption. Applications include financial trading desks and emergency (first-responder) service bureaus. The length of a Persistent Recording Sessions is independent from the length of the actual Communication Sessions. Persistent Recording Sessions avoid issues such as media clipping that can occur due to delays in Recording Session establishment.
The connection and attributes of media in the Recording Session are not dynamically signaled for each Communication Session before it can be recorded. Call details and metadata will still be signaled, but can be post- correlated to the recorded media. There will still need to be a means of correlating the recorded media connection/packets to the Communication Session, however this may be on a permanent filter-type basis, such as based on a SIP AoR of an agent that is always recorded, or based on identifiers in the recorded media itself.
In some cases, more than one concurrent Communication Session (on a single end-user apparatus, e.g. trading floor turret) is mixed into one Recording Session::
|-------- CS 1 -------|
|-------- CS 2 -------|
|-------- CS 3 -------|
RS |----------- Recording Session --------------|
| Figure 7 |
Use Case 5: Real-time Recording Controls.
For an active Recording Session, privacy or security reasons may demand not capturing a specific portion of a conversation. An example is for PCI (payment card industry) compliance where credit card info must be protected. One solution is to not record a caller speaking their credit card information.
Real-time controls may include Pause/Resume, or Mute/Unmute.
Use Case 6: IVR / Voice Portal Recording.
Self-service Interactive Voice Response (DTMF or ASR) applications may need to be recorded for application performance tuning or to meet compliance requirements.
Metadata about an IVR session recording must include session information and may include application context information (e.g. VoiceXML session variables, dialog names, etc.)
Use Case 7: Enterprise Mobility Recording.
Many agents and enterprise workers are not located on company premises.
Examples:
o Home-based agents or enterprise workers.
o Mobile phones of knowledge workers when they conduct work related (and legally required recording) calls. i.e. insurance agents, brokers, physicians.
Use Case 8: Geographically distributed or centralized recording.
Global banks with multiple branches up to thousands of small sites.
o Only phones and network infrastructure in branches, no recording services.
o Internal calls inside or between branches must be recorded.
o Centralized recording system in data centers together with telephony infrastructure (e.g. PBX).
Obtain media by forking:
o In data centers (inbound/outbound): fork media in gateway.
o At branch locations (internal): fork from end points or from site level gateways.
o Conference based solution is not applicable because it will require to reroute all communications via data centers.
Use Case 9: Record complex calls.
Record a call that is associated with another call.
Example:
o Customer in conversation with Agent
o Agent puts customer on hold in order to consult with a supervisor.
o Agent in conversation with Supervisor.
o Agent disconnects from Supervisor, reconnects with Customer.
o Each conversation is stored as a separate recording. The Supervisor call must be associated with the original customer call.
Use case 10: High-Availability, High Reliability Recording.
If recorder is not available at call setup time:
o Reject request to establish Communication Session.
o Redirect to alternate recorder.
If recorder has failed during a call, take specific action:
o Fail/Transfer call / fail over to a different recorder (may involve loss of recording during transition time).
o Failover recovery situation: continuation of a call recorded on a different recorder. Protocol must indicate that a Recording Session is a continuation of a previous Recording Session.
For some use cases, if recording is not available or failed in a middle of the call, original conversation has to be terminated or alerted as well.
Use Case 11: Record multi-channel, multi-media session.
Some applications require the recording of more than one media stream, possibly of different types. Media is synchronized, either at storage or at playback.
Speech analytics technologies (e.g. word spotting, emotion detection, speaker identification) may require speaker-separated recordings for optimum performance.
Multi-modal Contact Centers may include audio, video, IM or other interaction modalities.
In trading floors environments, in order to save resources, it may be preferable to mix multiple concurrent calls (Communication Sessions) on different handsets/speakers on the same turret into single recording session.
Use Case 12: Real-time media processing.
Recorder must support real-time media processing, such as speech analytics.
Recording and real-time analytics of trading floor interactions (including video and instant messaging). Real time analytics is required for automatic intervention (stopping interaction or alert) if for example, trader is not following regulations.
Speaker separation is required in order to reliably detect who is saying specific phrases.
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The following are requirements for the Session Recording Protocol:
o REQ-001 The mechanism MUST support Full-time Recording Sessions.
o REQ-002 The mechanism MUST support Selective Recording Sessions.
o REQ-003 The mechanism MUST support Dynamic (on-demand) Recording Sessions.
o REQ-004 The mechanism MUST support Persistent Recording Sessions.
o REQ-005 The mechanism MUST support establishing Recording Sessions from the RC to the RS. This requirement typically applies when the decision on whether a session should be recorded or not resides in the RC.
o REQ-006 The mechanism MUST support establishing Recording Sessions from the RS to the RC. This requirement typically applies when the decision on whether a session should be recorded or not resides in the RS.
o REQ-007 The mechanism MUST support the recording of IVR sessions.
o REQ-008 The mechanism SHOULD support RS failover and migration of Recording Sessions to a working RS without disconnecting the Communication Sessions.
o REQ-009 A request for a new Recording Session MUST be rejected by the Recording Server if service is unavailable (e.g. system overload, disk full, etc.)
o REQ-010 A request for a new Recording Session MUST be redirected to an available recorder server.
o REQ-011 If no recording resources are available, appropriate error message MUST be returned.
o REQ-012 The mechanism MUST support the ability to deliver mixed media streams to the RS. The RS MAY be informed about the composition of the mixed streams through session metadata.
Note: A mixed media stream is where several Communication Sessions are carried in a single Recording Session. A mixed media stream is typically produced by a mixer function.
o REQ-013 The mechanism MUST support the ability to deliver multiple media streams for a given Communication Session over separate Recording Sessions to the RS.
o REQ-014 The mechanism MUST support the ability to deliver multiple media streams for a given Communication Session over a single Recording Session to the RS.
o REQ-015 The mechanism MUST support the ability to pause and resume the Recording Session from the RC.
o REQ-016 The mechanism MUST support the ability to pause and resume the Recording Session from the RS.
o REQ-017 The mechanism MUST support the ability to correlate the request to record a call with the session being recorded.
o REQ-018 The mechanism MUST support the ability to correlate the request to record specific media sessions with the SIP session and media to be recorded (Recorded Session).
o REQ-019 The mechanism MUST support the ability to transport the metadata in the same SIP dialog as the Recording Session.
o REQ-020 The mechanism MUST support the ability to transport the metadata outside of the Recording Session SIP dialog.
o REQ-021 Metadata format must be agnostic of the transport protocol.
o REQ-022 The mechanism MUST support the ability to correlate metadata to the Recording Session.
o REQ-023 The mechanism MUST support a means for a SIP UA to request that a session is not recorded.
o REQ-024 The mechanism MUST provide an indication to the end users of a Communication Session that the session in which they are participating is being recorded.
Examples include: inject tones into the Communication Session from the RC, play a message at the beginning of a session, a visual indicator on a display, etc.
o REQ-025 A Recording Session may start at call setup.
o REQ-026 A Recording Session may start during a call.
o REQ-027 The mechanism SHOULD support means to avoid clipping media (leading or trailing samples) when the media is transported from the RC to the RS.
Note: Media clipping can occur due to delays in recording session establishment. RC implementations typically buffer some portion of the media to overcome this problem.
o REQ-028 Recorder MUST provide alarm notifications when a failure occurs.
o REQ-029 The mechanism MUST support a means of providing security (confidentiality, integrity and authentication) for the SIPREC.
o REQ-015 The mechanism MUST enable the Recording Session to identify itself as a SIP session that is established for the purpose of recording.
o REQ-016 The mechanism MUST support the existing SIP security model, including eavesdropping protection, authorization and authentication.
o REQ-032 if the Communication Session is encrypted, the Recording Session must not share the same keys.
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Session recording has substantial security implications, both for the SIP UA's being recorded, and for the Session Recording Protocol itself in terms of the RC and RS.
For the SIP UA's involved in the Communication Session, the requirements in this draft enable the UA to identify that a session is being recorded and for the UA to request that a given session is not subject to recording.
Since humans don't typically look at or know about protocol signaling such as SIP, and indeed the SIP session might have originated through a PSTN Gateway without any ability to pass on in-signaling indications of recording, users can be notified of recording in the media itself through voice announcements, a visual indicator on the endpoint, or other means.
With regards to security implications of the protocol(s), clearly there is a need for authentication, authorization, eavesdropping protection, and non-repudiation for the solution. The RC needs to know the RS it is communicating with is legitimate, and vice-versa, even if they are in different domains. Both the signaling and media for the SIPREC needs the ability to be authenticated and protected from eavesdropping and non-repudiation. Requirements are detailed in the requirements section.
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This document has no IANA actions.
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Thanks to Dan Wing, Alan Johnson, Vijay Gurbani and Cullen Jennings for their help with this document, and to all the members of the DISPATCH WG mailing list for providing valuable input to this work.
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In addition to the editors, the following people provided substantial technical and writing contributions to this document, listed alphabetically:
Hadriel Kaplan
Acme Packet
71 Third Ave.
Burlington, MA 01803
USA
hkaplan@acmepacket.com
Henry Lum
Genesys, Alcatel-Lucent
1380 Rodick Road, Suite 200
Markham, Ontario L3R 4G5
Canada
henry.lum@genesyslab.com
Martin Palmer
BT Global Services
Annandale House,1 Hanworth Road,
Sunbury on Thames Middlesex TW16 5DJ
UK
martin.4.palmer@bt.com
Dave Smith
Genesys, Alcatel-Lucent
2001 Junipero Serra Blvd, Daly City, CA 94014
USA
dsmith@genesyslab.com
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| [RFC2119] | Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” BCP 14, RFC 2119, March 1997 (TXT, HTML, XML). |
| [RFC2804] | IAB and IESG, “IETF Policy on Wiretapping,” RFC 2804, May 2000 (TXT). |
| [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 (TXT). |
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| Ken Rehor (editor) | |
| Cisco Systems | |
| 170 West Tasman Dr. | |
| Mail Stop SJC30/2/ | |
| San Jose, CA 95134 | |
| USA | |
| Email: | krehor@cisco.com |
| Rajnish Jain | |
| IPC Systems | |
| 777 Commerce Drive | |
| Fairfield, CT 06825 | |
| USA | |
| Email: | rajnish.jain@ipc.com |
| Leon Portman | |
| NICE Systems | |
| 8 Hapnina | |
| Ra'anana 43017 | |
| Israel | |
| Email: | leon.portman@nice.com |
| Andrew Hutton | |
| Siemens Enterprise Communications | |
| Email: | andrew.hutton@siemens-enterprise.com |
| URI: | http://www.siemens-enterprise.com |