One document matched: draft-ietf-siprec-req-01.txt
Differences from draft-ietf-siprec-req-00.txt
DISPATCH K. Rehor, Ed.
Internet-Draft Cisco Systems
Intended status: Informational R. Jain
Expires: February 2, 2011 IPC Systems
L. Portman
NICE Systems
A. Hutton
Siemens Enterprise Communications
August 31, 2010
Requirements for SIP-based Media Recording (SIPREC)
draft-ietf-siprec-req-01
Abstract
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.
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 February 2, 2011.
Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the
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document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Requirements notation . . . . . . . . . . . . . . . . . . . . 4
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Example Deployment Architectures . . . . . . . . . . . . . . . 6
5. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 12
7. Security Considerations . . . . . . . . . . . . . . . . . . . 14
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15
10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 15
11. Normative References . . . . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
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1. Requirements notation
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.
2. Introduction
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
Session Recording Server and Session 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] to record a media session
between a Session Recording Client and a Session Recording Server,
The Session Recording Client is the source of the recorded media.
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The Session 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 Session Recording Client to
the Session 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 Session
Recording Client purposefully streams media to a Session 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.
3. Definitions
Session Recording Server (SRS): A Session Recording Server (SRS) is a
SIP User Agent (UA) that is a specialized media server or collector
that acts as the sink of the recorded media. An SRS 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 SRS is typically implemented as a multi-port device that
is capable of receiving media from several sources simultaneously.
An SRS is typically also the sink of the recorded session metadata.
Note that the term "Server" does not imply the SRS is the server side
of a signaling protocol - the SRS may be the initiator of recording
requests, for example.
Session Recording Client (SRC): A Recording Client (SRC) is a SIP
User Agent (UA) that acts as the source of the recorded media,
sending it to the SRS. An SRC is a logical function. Its
capabilities may be implemented across one or more physical devices.
In practice, an SRC 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 SRC such that all such SIP entities
can be generically addressed under one definition. The SRC itself or
another entity working on its behalf (such as a SIP Application
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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 SRC and
SRS for the purpose of recording a Communication Session.
+---------------------------------------------------------------+
| (Session Recording Client) |
| +-------------+ +-----------+ |
| | | Communication Session | | |
| | A |<------------------------->| B | |
| | | | | |
| +-------------+ +-----------+ |
+---------------------------------------------------------------+
|
| Recording
| Session
|
v
+-------------+
| |
| Session |
| Recording |
| Server |
| |
+-------------+
Figure 1
Metadata: Data that describes the Communication Session and Recording
Session..
SIPREC: The set of SIP extensions that supports recording of
Communication Sessions.
Pause/Resume recording: Pause: Temporarily discontinue capture and
storage of the incoming media stream. Recording may continue via the
Resume command. Resume: Continue capture and storage of the incoming
media stream into the same recording session.
4. Example Deployment Architectures
A recording system deployment consists of the Recording Client and
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Recording Server. Recording Control is bi-directional; Recording
Media and Call Metadata are sent from the RC to RS.
+-------------+ +--------------+
| | Call Metadata | |
| Session |-------------------------->| Session |
| Recording | | Recording |
| Client | Recording Control | Server |
| (SRC) |<------------------------->| (SRS) |
| | | |
| | Recorded Media | |
| |-------------------------->| |
| | | |
+-------------+ +--------------+
Figure 2
5. Use Cases
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).
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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 single Recording Session captures
one or more Communication Sessions, in sequence (Fig. 6) or in
parallel (Fig. 7). The recording session is a single RTP stream,
therefore consists of a single offer/answer exchange. There may be
mid-session RE-INVITE offer/answer exchanges for codec changes or for
moving the RTP streams to handle failure scenarios.
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|--- 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; however, codec re-negotiation is possible. 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.
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.
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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.
Use Case 9: Record complex call scenarios.
Record a call that is associated with another call.
Example:
o Customer in conversation with Agent
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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 The Supervisor call must be associated with the original customer
call.
Use case 10: High availability and continuous recording.
Specific deployment scenarios present different requirements for
system availability, error handling, etc. including:
o An SRS must always be available at call setup time.
o No loss of media recording, including during failure of an SRS.
o The Communication Session must be terminated (or suitable
notification) in the event of a recording failure.
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.
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Speaker separation is required in order to reliably detect who is
saying specific phrases.
6. Requirements
The following are requirements for the Session Recording Protocol:
o REQ-000 The mechanism MUST provide a means for establishing,
maintaining and clearing Recording Sessions between a Session
Recording Client and a Session Recording Server for the purpose of
recording, at the Session Recording Server, media from Communication
Sessions.
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 SRC to the SRS. This requirement typically applies when the
decision about whether a session should be recorded or not resides in
the SRC.
o REQ-006 The mechanism MUST support establishing Recording Sessions
from the SRS to the SRC (SRS initiates recording). This requirement
typically applies when the decision about whether a session should be
recorded or not resides in the SRS.
o REQ-007 The mechanism MUST support the recording of IVR sessions.
o REQ-008 The mechanism SHOULD support SRS failover and migration of
Recording Sessions to a working SRS without disconnecting the
Communication Sessions.
o REQ-009 A request for a new Recording Session MUST be rejected by
the SRS 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 SRS.
o REQ-011 If no recording resources are available, appropriate error
message MUST be returned.
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o REQ-012 The mechanism MUST support the ability for an SRC to
deliver mixed audio streams from multiple Communication Sessions to
an SRS.
Note: A mixed audio stream is where several Communication Sessions
are carried in a single Recording Session. A mixed media stream is
typically produced by a mixer function. The RS MAY be informed about
the composition of the mixed streams through session metadata.
o REQ-012bis: The mechanism MUST support the ability for an SRC to
deliver mixed audio streams from different parties of a given
Communication Session to an SRS.
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 SRS.
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 SRS.
o REQ-015 The mechanism MUST support the ability to pause and resume
the Recording Session from the SRC.
o REQ-016 The mechanism MUST support the ability to pause and resume
the Recording Session from the SRS.
o REQ-017 The mechanism MUST provide the SRS with metadata describing
CSs that are being recorded, including the media being used and the
identities of parties involved.
o REQ-018 The mechanism MUST provide the SRS with the means to
correlate RS media with CS participant media described in metadata
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 a means to cancel and discard a
Recording Session during a Communication Session.
o REQ-023 The mechanism MUST support a means for a SIP UA to request
that a Communication Session is not recorded prior to recording.
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o REQ-024 The mechanism MUST provide a means of indicating 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 SRC, play a message at the beginning of a session, a visual
indicator on a display, etc.
o REQ-025 The mechanism MUST support the initiation of a Recording
Session at the beginning of a Communication Session.
o REQ-026 The mechanism MUST support the initiation of a Recording
Session during a Communication Session.
o REQ-027 The mechanism SHOULD support means to avoid clipping media
(leading or trailing samples) when the media is transported from the
SRC to the SRS.
Note: Media clipping can occur due to delays in recording session
establishment. SRC implementations typically buffer some portion of
the media to overcome this problem.
o REQ-028 The mechanism MUST NOT prevent high availability
deployments.
o REQ-029 The mechanism MUST support a means of providing security
(confidentiality, integrity and authentication) for the SIPREC.
o REQ-030 The mechanism MUST provide a means for the Recording
Session identifier so that the Recording Session itself is labeled as
a SIP session that is established for the purpose of recording.
o REQ-031 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 use different keys.
o REQ-033 The mechanism SHALL support means to relate Recording
Session(s) with Communication Session(s).
7. Security Considerations
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 SRC and SRS.
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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 SRC needs to
know the SRS 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.
8. IANA Considerations
This document has no IANA actions.
9. Acknowledgements
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.
10. Contributors
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
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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
11. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2804] IAB and IESG, "IETF Policy on Wiretapping", RFC 2804,
May 2000.
[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.
Authors' Addresses
Ken Rehor (editor)
Cisco Systems
170 West Tasman Dr.
Mail Stop SJC30/2/
San Jose, CA 95134
USA
Email: krehor@cisco.com
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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
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