From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc7879.txt | 731 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 731 insertions(+) create mode 100644 doc/rfc/rfc7879.txt (limited to 'doc/rfc/rfc7879.txt') diff --git a/doc/rfc/rfc7879.txt b/doc/rfc/rfc7879.txt new file mode 100644 index 0000000..918e214 --- /dev/null +++ b/doc/rfc/rfc7879.txt @@ -0,0 +1,731 @@ + + + + + + +Internet Engineering Task Force (IETF) R. Ravindranath +Request for Comments: 7879 T. Reddy +Category: Standards Track G. Salgueiro +ISSN: 2070-1721 Cisco + V. Pascual + Oracle + P. Ravindran + Nokia Networks + May 2016 + + + DTLS-SRTP Handling in SIP Back-to-Back User Agents + +Abstract + + Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs) + exist on the signaling and media paths between the endpoints. This + document describes the behavior of B2BUAs when Secure Real-time + Transport (SRTP) security context is set up with the Datagram + Transport Layer Security (DTLS) protocol. + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 7841. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc7879. + + + + + + + + + + + + + + + + + +Ravindranath, et al. Standards Track [Page 1] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 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 + 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 + 1.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 3 + 1.2. Goals and Scope of this Document . . . . . . . . . . . . 4 + 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 + 3. B2BUAs Procedures to Allow End-to-End DTLS-SRTP . . . . . . . 5 + 4. Signaling-Plane B2BUA Handling of DTLS-SRTP . . . . . . . . . 5 + 4.1. Proxy-B2BUAs . . . . . . . . . . . . . . . . . . . . . . 6 + 4.2. Signaling-Only and SDP-Modifying Signaling-Only B2BUAs . 6 + 5. Media-Plane B2BUA Handling of DTLS-SRTP . . . . . . . . . . . 6 + 5.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 6 + 5.1.1. Media Relay . . . . . . . . . . . . . . . . . . . . . 6 + 5.1.2. RTP- and RTCP-Aware Media-Aware B2BUA . . . . . . . . 8 + 6. Forking Considerations . . . . . . . . . . . . . . . . . . . 9 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 + 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 + 8.1. Normative References . . . . . . . . . . . . . . . . . . 11 + 8.2. Informative References . . . . . . . . . . . . . . . . . 11 + Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 12 + Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 12 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 + + + + + + + + + + + + + + +Ravindranath, et al. Standards Track [Page 2] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + +1. Introduction + +1.1. Overview + + [RFC5763] describes how the Session Initiation Protocol (SIP) + [RFC3261] can be used to establish a Secure Real-time Transport + Protocol (SRTP) [RFC3711] security context with the Datagram + Transport Layer Security (DTLS) protocol [RFC6347]. It describes a + mechanism for transporting a certificate fingerprint using the + Session Description Protocol (SDP) [RFC4566]. The fingerprint + identifies the certificate that will be presented during the DTLS + handshake. DTLS-SRTP is currently defined for point-to-point media + sessions, in which there are exactly two participants. Each DTLS- + SRTP session (described in Section 3 of [RFC5764]) contains a single + DTLS connection (if RTP and RTP Control Protocol (RTCP) are + multiplexed) or two DTLS connections (if RTP and RTCP are not + multiplexed), and either two SRTP contexts (if media traffic is + flowing in both directions on the same 5-tuple) or one SRTP context + (if media traffic is only flowing in one direction). + + In many SIP deployments, SIP Back-to-Back User Agents (B2BUA) + entities exist on the SIP-signaling path between the endpoints. As + described in [RFC7092], these B2BUAs can modify SIP and SDP + information. For example, as described in Section 3.1.3 of + [RFC7092], SDP-modifying signaling-only B2BUAs can potentially modify + the SDP. B2BUAs can also be present on the media path, in which case + they modify parts of the SDP information (like IP address, port) and + subsequently modify the RTP headers as well. Such B2BUAs are + referred to as "media-plane B2BUAs". [RFC7092] describes two + different categories of media-plane B2BUAs, according to the level of + activities performed on the media plane. + + When B2BUAs are present in a call between two SIP User Agents (UAs), + they often make end-to-end DTLS-SRTP sessions impossible. An "end- + to-end DTLS-SRTP session" means that man-in-the-middle devices cannot + break the DTLS-SRTP session between the endpoints. In other words, + the man-in-the-middle device cannot create a separate DTLS-SRTP + session between the client and the middle device on one side, and the + middle device and the remote peer on the other side. B2BUAs may be + deployed for address hiding or media latching [RFC7362], although + Traversal Using Relays around NAT (TURN) and Interactive Connectivity + Establishment (ICE) are expected to be used more often for this + purpose as it provides better security properties. Such B2BUAs are + able to perform their functions without requiring termination of + DTLS-SRTP sessions, i.e., these B2BUAs need not act as DTLS proxy and + decrypt the RTP payload. + + + + + +Ravindranath, et al. Standards Track [Page 3] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + +1.2. Goals and Scope of this Document + + A B2BUA could be deployed for address hiding or media latching as + described in [RFC7362]. Such B2BUAs only terminate the media plane + at the IP and transport (UDP/TCP) layers and may inspect the RTP + headers or RTP Control Protocol (RTCP) packets. The goal of this + specification is to provide guidance on how such B2BUAs function + without breaking the end-to-end DTLS-SRTP session. A B2BUA could + also terminate the media, or modify the RTP headers or RTP Control + Protocol (RTCP) packets. Such B2BUAs will not allow end-to-end DTLS- + SRTP. The recommendations made in this document are not expected to + be applied by B2BUAs terminating DTLS-SRTP sessions given deployment + reality. + + This specification assumes that a B2BUA is not providing identity + assurance and is not authorized to terminate the DTLS-SRTP session. + A B2BUA that provides identity assurance on behalf of endpoints + behind it can modify any portion of SIP and SDP before it generates + the identity signature. As the B2BUA is generating the identity + signature, it is not possible to detect if a B2BUA has terminated the + DTLS-SRTP session. B2BUAs providing identity assurance and + terminating DTLS-SRTP sessions are out of scope of this document. + + The following sections describe the behavior B2BUAs can follow to + avoid breaking end-to-end DTLS-SRTP sessions. + +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]. + + Transport Address: The combination of an IP address and port number. + + The following generalized terms are defined in [RFC3261], Section 6. + + B2BUA: A SIP Back-to-Back User Agent, which is the logical + combination of a User Agent Server (UAS) and a User Agent Client + (UAC). + + UAS: A SIP User Agent Server. + + UAC: A SIP User Agent Client. + + All of the pertinent B2BUA terminology and taxonomy used in this + document are based on [RFC7092]. + + + + + +Ravindranath, et al. Standards Track [Page 4] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + + It is assumed the reader is already familiar with the fundamental + concepts of the RTP protocol [RFC3550] and its taxonomy [RFC7656], as + well as those of SRTP [RFC3711] and DTLS [RFC6347]. + +3. B2BUAs Procedures to Allow End-to-End DTLS-SRTP + + A B2BUA MUST follow the rules mentioned below to allow end-to-end + DTLS-SRTP sessions. + + 1. B2BUAs MUST forward the certificate fingerprint and SDP setup + attribute it receives from one endpoint unmodified towards the + other endpoint and vice versa. + + 2. The enhancements described in [RFC4474] provide a means for + signing portions of SIP requests in order to provide identity + assurance and certificate pinning by providing an identity + signature over the SDP that carries the fingerprint of keying for + DTLS-SRTP [RFC5763]. B2BUAs can identify that the enhancements + in [RFC4474] are used for identity assurance if the SIP request + contains both Identity and Identity-Info headers. In cases where + endpoints use [RFC4474], B2BUAs MUST ensure that it does not + modify any of the information used to construct the identity + signature. This includes the entire SDP body and portions of the + SIP header as described in [RFC4474]. In this case, a B2BUA + cannot act as a media-relay B2BUA. + + 3. [SIP-ID] is introduced to overcome the limitations of [RFC4474] + (discussed in Section 1 of [SIP-ID]). Unlike [RFC4474], [SIP-ID] + does not generate an identity signature over material that + intermediaries in the field commonly alter. In this case, a + B2BUA can act as a media-relay B2BUA. B2BUAs can identify that + [SIP-ID] is used for identity assurance if the SIP request + contains an Identity header but does not include an Identity-Info + header. The Identity-Info header is deprecated in [SIP-ID]. A + B2BUA MUST ensure that it does not modify any of the headers used + to construct the identity signature. + + 4. Both media relays and media-aware relays MUST NOT modify the + authenticated portion of RTP and RTCP packets, and MUST NOT + modify the authentication tag in the RTP and RTCP packets. + +4. Signaling-Plane B2BUA Handling of DTLS-SRTP + + Section 3.1 of [RFC7092] describes different categories of signaling- + plane B2BUAs. This section explains how these B2BUAs are expected to + comply with the recommendations in Section 3. + + + + + +Ravindranath, et al. Standards Track [Page 5] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + +4.1. Proxy-B2BUAs + + Proxy-B2BUAs, as defined in Section 3.1.1 of [RFC7092], modify only + the Via and Record-Route SIP headers. These B2BUAs can continue to + perform their function and still allow end-to-end DTLS-SRTP sessions + since none of the headers used to construct the identity signature + are modified. + +4.2. Signaling-Only and SDP-Modifying Signaling-Only B2BUAs + + These categories of B2BUAs are likely to modify headers that are used + to construct the identity signature. For example, a signaling-only + B2BUA can modify the Contact URI. Such B2BUAs are likely to violate + rule 2 or rule 3 in Section 3. Depending upon the application + requirements, such a B2BUA may be able to limit modification of + header fields to those allowed to be modified by [RFC4474] or + [SIP-ID]. + +5. Media-Plane B2BUA Handling of DTLS-SRTP + +5.1. General + + This section describes how the different types of media-plane B2BUAs + defined in [RFC7092] are expected to comply with the recommendations + in Section 3. + +5.1.1. Media Relay + + From an application-layer point of view, a media relay (as defined in + Section 3.2.1 of [RFC7092]) forwards all packets it receives on a + negotiated connection, without inspecting or modifying the packet + contents. A media relay only modifies the transport layer (UDP/TCP) + and IP headers. + + A media-relay B2BUA follows rule 1 mentioned in Section 3 and + forwards the certificate fingerprint and SDP setup attribute it + receives from one endpoint unmodified towards the other endpoint and + vice versa. The following example shows a SIP call establishment + flow, with both SIP endpoints (user agents) using DTLS-SRTP, and a + media-relay B2BUA. + + + + + + + + + + + +Ravindranath, et al. Standards Track [Page 6] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + + +-------+ +-------------------+ +-----+ + | Alice | | Media-Relay B2BUA | | Bob | + +-------+ +-------------------+ +-----+ + |(1) INVITE | (3) INVITE | + | a=setup:actpass | a=setup:actpass | + | a=fingerprint1 | a=fingerprint1 | + | (Alice's IP/port) | (B2BUAs IP/port) | + |------------------------>|-------------------------->| + | | | + | (2) 100 trying | | + |<------------------------| | + | | (4) 100 trying | + | |<--------------------------| + | | | + | | (5) 200 OK | + | | a=setup:active | + | | a=fingerprint2 | + | | (Bob's IP/port) | + |<------------------------|<--------------------------| + | (6) 200 OK | | + | a=setup:active | | + | a=fingerprint2 | | + | B2BUAs IP/port | | + | (7, 8) ClientHello + use_srtp | + |<----------------------------------------------------| + |(B2BUA changes transport(UDP/TCP) and IP header) | + | | | + | | | + | (9,10) ServerHello + use_srtp | + |---------------------------------------------------->| + |(B2BUA changes transport(UDP/TCP) and IP header) | + | | | + | | | + | (11) | | + | [Certificate exchange between Alice and Bob over | + | DTLS ] | | + | | | + | (12) | | + |<---------SRTP/SRTCP-----------SRTP/SRTCP----------->| + | [B2BUA changes transport(UDP/TCP) and IP headers] | + + Figure 1: INVITE with SDP Call Flow for Media-Relay B2BUA + + Note: For brevity, the entire value of the SDP fingerprint attribute + is not shown. The example here shows only one DTLS connection for + the sake of simplicity. In reality, depending on whether the RTP and + RTCP flows are multiplexed or demultiplexed, there will be one or two + DTLS connections. + + + +Ravindranath, et al. Standards Track [Page 7] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + + If RTP and RTCP traffic is multiplexed on a single port as described + in [RFC5761], then only a single DTLS connection is required between + the peers. If RTP and RTCP are not multiplexed, then the peers would + have to establish two DTLS connections. In this case, after + receiving an INVITE request, Bob triggers the establishment of a DTLS + connection. Note that the DTLS handshake and the sending of the + INVITE response can happen in parallel; thus, the B2BUA has to be + prepared to receive DTLS, Session Traversal Utilities for NAT (STUN), + and media on the ports it advertised to Bob in the SDP offer before + it receives an SDP answer from Bob. Since a media-relay B2BUA does + not differentiate between a DTLS message, RTP, or any packet it + receives, it only changes the transport layer (UDP/TCP) and IP + headers and forwards the packet towards the other endpoint. The + B2BUA cannot decrypt the RTP payload, as the payload is encrypted + using the SRTP keys derived from the DTLS connection setup between + Alice and Bob. + + If the endpoints use [RFC4474], a B2BUA cannot function as a media- + relay without violating rule 2 in Section 3. If [SIP-ID] is used, a + B2BUA can modify the IP address in the c= line and the port in the m= + line in the SDP as long as it does not otherwise violate rule 3 in + Section 3. + +5.1.2. RTP- and RTCP-Aware Media-Aware B2BUA + + Unlike the media relay discussed in Section 5.1.1, a media-aware + relay as defined in Section 3.2.2 of [RFC7092] is aware of the type + of media traffic it is receiving. There are two types of media-aware + relays, those that merely inspect the RTP headers and unencrypted + portions of RTCP packets, and those that inspect and modify the RTP + headers and unencrypted portions of RTCP packets. + +5.1.2.1. RTP Header and RTCP Packets Inspection + + An RTP-/RTCP-aware media relay does not modify the RTP headers and + RTCP packets but only inspects the packets. Such B2BUAs follow rule + 4 in Section 3 and can continue to do their function while allowing + end-to-end DTLS-SRTP. Inspection by the B2BUA will not reveal the + clear-text for encrypted parts of the SRTP/SRTCP packets. + +5.1.2.2. RTP Header and RTCP Packet Modification + + A B2BUA cannot modify RTP headers or RTCP packets, as to do so it + would need to act as a DTLS endpoint, terminate the DTLS-SRTP + session, and decrypt/re-encrypt RTP packets. If a B2BUA modifies + unencrypted or encrypted portions of the RTP or RTCP packets, then + the integrity check will fail and the packet will be dropped by the + endpoint. The unencrypted and encrypted portions of the RTP or RTCP + + + +Ravindranath, et al. Standards Track [Page 8] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + + packets are integrity protected using the HMAC algorithm negotiated + during the DTLS handshake (discussed in Section 4.1.2 of [RFC5764]). + B2BUAs have to follow the rules in Section 3 to avoid breaking the + integrity of SRTP/SRTCP streams. + +6. Forking Considerations + + Due to forking [RFC3261], a SIP request carrying an SDP offer sent by + an endpoint (offerer) can reach multiple remote endpoints. As a + result, multiple DTLS-SRTP sessions can be established, one between + the endpoint that sent the SIP request and each of the remote + endpoints that received the request. B2BUAs have to follow rule 1 in + Section 3 while handling offer/answer and forward the certificate + fingerprints and SDP setup attributes it received in the SDP answer + from each endpoint (answerer) unmodified towards the offerer. Since + each DTLS connection is set up on a unique 5-tuple, B2BUA replaces + the answerer's transport addresses in each answer with its unique + transport addresses so that the offerer can establish a DTLS + connection with each answerer. The B2BUA, acting as a media relay + here, follows rule 4 mentioned in Section 3. + + Bob (192.0.2.1:6666) + / + / + / DTLS-SRTP=XXX + / + / + DTLS-SRTP=XXX v + <-----------> (192.0.2.3:7777) + Alice (192.0.2.0:5555) B2BUA + <-----------> (192.0.2.3:8888) + DTLS-SRTP=YYY ^ + \ + \ DTLS-SRTP=YYY + \ + \ + \ + Charlie (192.0.2.2:6666) + + Figure 2: B2BUA Handling Multiple Answers + + For instance, as shown in Figure 2, Alice sends a request with an + offer and the request is forked. Alice receives answers from both + Bob and Charlie. The B2BUA advertises different B2BUA transport + addresses in each answer, as shown in Figure 2, where XXX and YYY + represent different DTLS-SRTP sessions. The B2BUA replaces Bob's + transport address (192.0.2.1:6666) in the answer with its transport + address (192.0.2.3:7777) and Charlie's transport address + + + +Ravindranath, et al. Standards Track [Page 9] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + + (192.0.2.2:6666) in the answer with its transport address + (192.0.2.3:8888). The B2BUA tracks the remote sources (Bob and + Charlie) and associates them to the local sources that are used to + send packets to Alice. + +7. Security Considerations + + This document describes the behavior B2BUAs must follow to avoid + breaking end-to-end DTLS-SRTP. Media relays that modify RTP or RTCP, + or modify SIP header fields or SDP fields that are protected by the + identity signature, are incompatible with end-to-end DTLS-SRTP. Such + relays are out of scope for this document. Security considerations + discussed in [RFC5763] are also applicable to this document. In + addition, the B2BUA behaviors outlined in this document do not impact + the security and integrity of a DTLS-SRTP session or the data + exchanged over it. A malicious B2BUA can try to break into the DTLS + connection, but such an attack can be prevented using the identity + validation mechanism discussed in [RFC4474] or [SIP-ID]. Either the + endpoints or the authentication service proxies involved in the call + can use the identity validation mechanisms discussed in [RFC4474] or + [SIP-ID] to validate the identity of peers and detect malicious + B2BUAs that can attempt to terminate the DTLS connection to decrypt + the RTP payload. + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Ravindranath, et al. Standards Track [Page 10] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + +8. References + +8.1. 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, + . + + [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. + Jacobson, "RTP: A Transport Protocol for Real-Time + Applications", STD 64, RFC 3550, DOI 10.17487/RFC3550, + July 2003, . + + [RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. + Norrman, "The Secure Real-time Transport Protocol (SRTP)", + RFC 3711, DOI 10.17487/RFC3711, March 2004, + . + + [RFC5763] Fischl, J., Tschofenig, H., and E. Rescorla, "Framework + for Establishing a Secure Real-time Transport Protocol + (SRTP) Security Context Using Datagram Transport Layer + Security (DTLS)", RFC 5763, DOI 10.17487/RFC5763, May + 2010, . + + [RFC5764] McGrew, D. and E. Rescorla, "Datagram Transport Layer + Security (DTLS) Extension to Establish Keys for the Secure + Real-time Transport Protocol (SRTP)", RFC 5764, + DOI 10.17487/RFC5764, May 2010, + . + + [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer + Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347, + January 2012, . + +8.2. Informative References + + [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, + . + + [RFC4474] Peterson, J. and C. Jennings, "Enhancements for + Authenticated Identity Management in the Session + Initiation Protocol (SIP)", RFC 4474, + DOI 10.17487/RFC4474, August 2006, + . + + + +Ravindranath, et al. Standards Track [Page 11] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + + [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session + Description Protocol", RFC 4566, DOI 10.17487/RFC4566, + July 2006, . + + [RFC5761] Perkins, C. and M. Westerlund, "Multiplexing RTP Data and + Control Packets on a Single Port", RFC 5761, + DOI 10.17487/RFC5761, April 2010, + . + + [RFC7092] Kaplan, H. and V. Pascual, "A Taxonomy of Session + Initiation Protocol (SIP) Back-to-Back User Agents", + RFC 7092, DOI 10.17487/RFC7092, December 2013, + . + + [RFC7362] Ivov, E., Kaplan, H., and D. Wing, "Latching: Hosted NAT + Traversal (HNT) for Media in Real-Time Communication", + RFC 7362, DOI 10.17487/RFC7362, September 2014, + . + + [RFC7656] Lennox, J., Gross, K., Nandakumar, S., Salgueiro, G., and + B. Burman, Ed., "A Taxonomy of Semantics and Mechanisms + for Real-Time Transport Protocol (RTP) Sources", RFC 7656, + DOI 10.17487/RFC7656, November 2015, + . + + [SIP-ID] Peterson, J., Jennings, C., Rescorla, E., and C. Wendt, + "Authenticated Identity Management in the Session + Initiation Protocol (SIP)", Work in Progress, + draft-ietf-stir-rfc4474bis-09, May 2016 + +Acknowledgments + + Special thanks to Lorenzo Miniero, Ranjit Avarsala, Hadriel Kaplan, + Muthu Arul Mozhi, Paul Kyzivat, Peter Dawes, Brett Tate, Dan Wing, + Charles Eckel, Simon Perreault, Albrecht Schwarz, Jens Guballa, + Christer Holmberg, Colin Perkins, Ben Campbell, and Alissa Cooper for + their constructive comments, suggestions, and early reviews that were + critical to the formulation and refinement of this document. The + authors would also like to thank Dan Romascanu, Vijay K. Gurbani, + Francis Dupont, Paul Wouters, and Stephen Farrell for their review + and feedback of this document. + +Contributors + + Rajeev Seth provided substantial contributions to this document. + + + + + + +Ravindranath, et al. Standards Track [Page 12] + +RFC 7879 DTLS-SRTP Handling in SIP B2BUA May 2016 + + +Authors' Addresses + + Ram Mohan Ravindranath + Cisco + Cessna Business Park + Sarjapur-Marathahalli Outer Ring Road + Bangalore, Karnataka 560103 + India + + Email: rmohanr@cisco.com + + + Tirumaleswar Reddy + Cisco + Cessna Business Park + Sarjapur Marathalli Outer Ring Road + Bangalore, Karnataka 560103 + India + + Email: tireddy@cisco.com + + + Gonzalo Salgueiro + Cisco Systems, Inc. + 7200-12 Kit Creek Road + Research Triangle Park, NC 27709 + United States + + Email: gsalguei@cisco.com + + + Victor Pascual + Oracle + Barcelona, Spain + + Email: victor.pascual.avila@oracle.com + + + Parthasarathi Ravindran + Nokia Networks + Bangalore, Karnataka + India + + Email: partha@parthasarathi.co.in + + + + + + + +Ravindranath, et al. Standards Track [Page 13] + -- cgit v1.2.3