Network Working Group E. Ertekin Internet-Draft C. Christou Expires: June 7, 2010 Booz Allen Hamilton C. Bormann Universitaet Bremen TZI December 4, 2009 IPsec Extensions to Support Robust Header Compression over IPsec (ROHCoIPsec) draft-ietf-rohc-ipsec-extensions-hcoipsec-06 Abstract Integrating ROHC with IPsec (ROHCoIPsec) offers the combined benefits of IP security services and efficient bandwidth utilization. However, in order to integrate ROHC with IPsec, extensions to the SPD and SAD are required. This document describes the IPsec extensions required to support ROHCoIPsec. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on June 7, 2010. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. Ertekin, et al. Expires June 7, 2010 [Page 1] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 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 BSD License. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Ertekin, et al. Expires June 7, 2010 [Page 2] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Extensions to IPsec Databases . . . . . . . . . . . . . . . . 3 3.1. Security Policy Database (SPD) . . . . . . . . . . . . . . 3 3.2. Security Association Database (SAD) . . . . . . . . . . . 5 4. Extensions to IPsec Processing . . . . . . . . . . . . . . . . 6 4.1. Addition to the IANA Protocol Numbers Registry . . . . . . 6 4.2. Verifying the Integrity of Decompressed Packet Headers . . 6 4.2.1. ICV Computation and Integrity Verification . . . . . . 7 4.3. ROHC Segmentation and IPsec Tunnel MTU . . . . . . . . . . 7 4.4. Nested IPComp and ROHCoIPsec Processing . . . . . . . . . 9 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 Appendix A. ASN.1 representation for ROHCoIPsec . . . . . . . . . 10 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12 8.1. Normative References . . . . . . . . . . . . . . . . . . . 12 8.2. Informative References . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 Ertekin, et al. Expires June 7, 2010 [Page 3] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 1. Introduction Using IPsec ([IPSEC]) protection offers various security services for IP traffic. However, these benefits come at the cost of additional packet headers, which increase packet overhead. As described in [ROHCOIPSEC], Robust Header Compression (ROHC [ROHC]) can be used with IPsec to reduce the overhead associated with IPsec-protected packets. IPsec-protected traffic is carried over Security Associations (SAs), whose parameters are negotiated on a case-by-case basis. The Security Policy Database (SPD) specifies the services that are to be offered to IP datagrams, and the parameters associated with SAs that have been established are stored in the Security Association Database (SAD). For ROHCoIPsec, various extensions to the SPD and SAD that incorporate ROHC-relevant parameters are required. In addition, three extensions to IPsec processing are required. First, a mechanism for identifying ROHC packets must be defined. Second, a mechanism to ensure the integrity of the decompressed packet is needed. Finally, the order of the inbound and outbound processing must be enumerated when nesting IP Compression (IPComp [IPCOMP]), ROHC, and IPsec processing. 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 RFC 2119 [BRA97]. 3. Extensions to IPsec Databases The following subsections specify extensions to the SPD and the SAD that MUST be supported for ROHCoIPsec. Appendix A provides an example ASN.1 representation of the ROHC parameters that are included in the SPD. 3.1. Security Policy Database (SPD) In general, the SPD is responsible for specifying the security services that are offered to IP datagrams. Entries in the SPD specify how to derive the corresponding values for SAD entries. To support ROHC, the SPD is extended to include per-channel ROHC parameters. Together, the existing IPsec SPD parameters and the ROHC parameters will dictate the security and header compression services that are provided to packets. Ertekin, et al. Expires June 7, 2010 [Page 4] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 The fields contained within each SPD entry are defined in RFC 4301 [IPSEC], Section 4.4.1.2. To support ROHC, several processing info fields are added to the SPD; these fields contain information regarding the ROHC profiles and channel parameters supported by the local ROHC instance. If the processing action associated with the selector sets is PROTECT, then the processing info must be extended with the following ROHC channel parameters: MAX_CID: The field indicates the highest context ID that will be decompressed by the local decompressor. MAX_CID MUST be at least 0 and at most 16383 (The value 0 implies having one context). MRRU: The MRRU parameter indicates the size of the largest reconstructed unit (in octets) that the local decompressor is expected to reassemble from ROHC segments. This size includes the CRC and the ROHC ICV. NOTE: Since in-order delivery of ROHC packets cannot be guaranteed, the MRRU parameter SHOULD be set to 0 (as stated in Section 5.2.5.1 of RFC 4995 [ROHC] and Section 6.1 of RFC 5225 [ROHCV2]), which indicates that no segment headers are allowed on the ROHCoIPsec channel. PROFILES: This field is a list of ROHC profiles supported by the local decompressor. Possible values for this list are contained in the ROHC Profile Identifiers registry [ROHCPROF]. In addition to these ROHC channel parameters, a ROHC Integrity Algorithm and a ROHC ICV Length field MUST be included within the SPD: ROHC INTEGRITY ALGORITHM: This field is a list of integrity algorithms supported by the ROHCoIPsec instance. This will be used by the ROHC process to ensure that packet headers are properly decompressed (see Section 4.2). Authentication algorithms that MUST be supported are specified in the "Authentication Algorithms" table in section 3.1.1 ("ESP Encryption and Authentication Algorithms") of RFC 4835 [CRYPTO- ALG] (or its successor). ROHC ICV LENGTH: This field specifies the length of the ICV that is used in conjunction with the ROHC Integrity Algorithm. Several other ROHC channel parameters are omitted from the SPD, because they are set implicitly. The omitted channel parameters are LARGE_CIDS and FEEDBACK_FOR. The LARGE_CIDS channel parameter MUST be set based on the value of MAX_CID (e.g. if MAX_CID is <= 15, LARGE_CIDS is assumed to be 0). Finally, the ROHC FEEDBACK_FOR Ertekin, et al. Expires June 7, 2010 [Page 5] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 channel parameter MUST be set to the ROHC channel associated with the SA in the reverse direction. If an SA in the reverse direction does not exist, the FEEDBACK_FOR channel parameter is not set, and ROHC MUST NOT operate in bidirectional Mode. 3.2. Security Association Database (SAD) Each entry within the SAD defines the parameters associated with each established SA. Unless the "populate from packet" (PFP) flag is asserted for a particular field, SAD entries are determined by the corresponding SPD entries during the creation of the SA. The data items contained within the SAD are defined in RFC 4301 [IPSEC], Section 4.4.2.1. To support ROHC, the SAD must include a "ROHC Data Item"; this data item contains parameters used by ROHC instance. The ROHC Data Item exists for both inbound and outbound SAs. The ROHC Data Item includes the ROHC channel parameters for the SA. These channel parameters (i.e., MAX_CID, PROFILES, MRRU) are enumerated above in Section 3.1. For inbound SAs, the ROHC Data Item MUST specify the ROHC channel parameters that are used by the local decompressor instance; conversely, for outbound SAs, the ROHC Data Item MUST specify the ROHC channel parameters that are used by local compressor instance. In addition to these ROHC channel parameters, the ROHC Data Item for both inbound and outbound SAs MUST include three additional parameters. Specifically, these parameters store the integrity algorithm, the algorithm's respective key, and the ICV length that is used by the ROHC process (see Section 3.2). The integrity algorithm and its associated key are used to calculate a ROHC ICV of the specified length; this ICV is used to verify the packet headers post- decompression. Finally, for inbound SAs, the ROHC Data Item MUST include a FEEDBACK_FOR parameter. The parameter is a reference to a ROHC channel in the opposite direction (i.e., the outbound SA) between the same compression endpoints. A ROHC channel associated with an inbound SA and a ROHC channel associated with an outbound SA MAY be coupled to form a Bi-directional ROHC channel as defined in Section 6.1 and Section 6.2 in RFC 3759 [ROHC-TERM]. "ROHC Data Item" values MAY be initialized manually (i.e., administratively configured for manual SAs), or initialized via a key exchange protocol (e.g. IKEv2 [IKEV2]) that has been extended to support the signaling of ROHC parameters [IKEV2EXT]. Ertekin, et al. Expires June 7, 2010 [Page 6] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 4. Extensions to IPsec Processing 4.1. Addition to the IANA Protocol Numbers Registry In order to demultiplex header-compressed from uncompressed traffic on a ROHC-enabled SA, a "ROHC" value must be reserved in the IANA Protocol Numbers registry. If an outbound packet has a compressed header, the Next Header field of the security protocol header (e.g., AH [AH], ESP [ESP]) MUST be set to the "ROHC" protocol identifier. If the packet header has not been compressed by ROHC, the Next Header field does not contain the "ROHC" protocol identifier. Conversely, for an inbound packet, the value of the security protocol Next Header field MUST be checked to determine if the packet includes a ROHC header, in order to determine if it requires ROHC decompression. Use of the "ROHC" protocol identifier for purposes other than ROHCOIPsec is currently not defined. Future protocols that make use of the allocation (e.g., other applications of ROHC in multi-hop environments) require specification of the logical compression channel between the ROHC compressor and decompressor. In addition, these specifications will require the investigation of the security considerations associated with use of the "ROHC" protocol identifier outside the context of the next-header field of security protocol headers. 4.2. Verifying the Integrity of Decompressed Packet Headers Since ROHC is inherently a lossy compression algorithm, ROHCoIPsec MAY use an additional Integrity Algorithm (and respective key) to compute a second Integrity Check Value (ICV) for the uncompressed packet. This ICV MUST be computed over the uncompressed IP header, as well at the higher-layer headers and the packet payload. When computed, the ICV is appended to the ROHC-compressed packet. At the decompressor, the decompressed packet (including the uncompressed IP header, higher-layer headers, and packet payload; but not including the authentication data) will be used with the integrity algorithm (and its respective key) to compute a value that will be compared to the appended ICV. If these values are not identical, the decompressed packet MUST be dropped. Figure 1 illustrates the composition of a ROHCoIPsec-processed IPv4 packet. In the example, TCP/IP compression is applied, and the packet is processed with tunnel mode ESP. Ertekin, et al. Expires June 7, 2010 [Page 7] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 BEFORE COMPRESSION AND APPLICATION OF ESP ---------------------------- IPv4 |orig IP hdr | | | |(any options)| TCP | Data | ---------------------------- AFTER ROHCOIPSEC COMPRESSION AND APPLICATION OF ESP ------------------------------------------------------ IPv4 | new IP hdr | | Cmpr. | | ROHC | ESP | ESP| |(any options)| ESP | Hdr. |Data| ICV |Trailer| ICV| ------------------------------------------------------ Figure 1. Example of a ROHCoIPsec-processed packet. Note: At the decompressor, the ROHC ICV field is not included in the calculation of the ROHC ICV. 4.2.1. ICV Computation and Integrity Verification In order to correctly verify the integrity of the decompressed packets, the processing steps for ROHCoIPsec MUST be implemented in a specific order, as given below. For outbound packets that are processed by ROHC and IPsec-protected: o Compute an ICV for the uncompressed packet with the negotiated (ROHC) integrity algorithm and its respective key o Compress the packet headers (as specified by the ROHC process) o Append the ICV to the compressed packet o Apply AH or ESP processing to the packet, as specified in the appropriate SAD entry For inbound packets that are to be decompressed by ROHC: o Apply AH or ESP processing, as specified in the appropriate SAD entry o Remove the ICV from the packet o Decompress the packet header(s) o Compute an ICV for the decompressed packet with the negotiated (ROHC) integrity algorithm and its respective key o Compare the computed ICV to the original ICV calculated at the compressor: if these two values differ, the packet MUST be dropped; otherwise resume IPsec processing 4.3. ROHC Segmentation and IPsec Tunnel MTU In certain scenarios, a ROHCoIPsec-processed packet may exceed the size of the IPsec tunnel MTU. RFC 4301 [IPSEC] currently stipulates the following for outbound traffic that exceeds the SA PMTU: Ertekin, et al. Expires June 7, 2010 [Page 8] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 Case 1: Original (cleartext) packet is IPv4 and has the DF bit set. The implementation should discard the packet and send a PMTU ICMP message. Case 2: Original (cleartext) packet is IPv4 and has the DF bit clear. The implementation should fragment (before or after encryption per its configuration) and then forward the fragments. It should not send a PMTU ICMP message. Case 3: Original (cleartext) packet is IPv6. The implementation should discard the packet and send a PMTU ICMP message. For ROHCoIPsec, Cases 1 and 3, and the post-encryption fragmentation for Case 2 are employed. However, since current ROHC compression profiles do not support the compression of IP packet fragments, pre- encryption fragmentation is not compatible with the current set of ROHC profiles. In place of pre-encryption fragmentation, ROHC segmentation MAY be used at the compressor to divide the packet, where each segment conforms to the tunnel MTU. However, because in- order delivery of ROHC segments is not guaranteed, the use of ROHC segmentation is not recommended. If the compressor determines that the compressed packet exceeds the tunnel MTU, ROHC segmentation MAY be applied to the compressed packet before AH or ESP processing. This determination can be made by comparing the anticipated ROHCoIPsec packet size to the Path MTU data item specified in the SAD entry. If the MRRU for the channel is non- zero, the compressor applies ROHC segmentation. If segmentation is applied, the process MUST account for the additional overhead imposed by IPsec process (e.g., AH or ESP overhead, crypto synchronization data, the additional IP header, etc.) such that the final IPsec- processed segments are less than the tunnel MTU. After segmentation, each ROHC segment is consecutively processed by the appropriate security protocol (e.g., AH, ESP) instantiated on the ROHC-enabled SA. Since ROHC segments are processed consecutively, the associated AH/ESP sequence number MUST be incremented by one for each segment transmitted over the ROHC channel. As such, after all ROHC segments receive AH/ESP processing, these segments can be identified (at the remote IPsec implementation) by a range of contiguous AH/ESP sequence numbers. For channels where the MRRU is non-zero, the ROHCoIPsec decompressor MUST re-assemble the ROHC segments that are received. To accomplish this, the decompressor MUST identify the ROHC segments (as documented in Section 5.2.6 of RFC 4995 [ROHC]), and attempt reconstruction using the ROHC segmentation protocol (Section 5.2.5 of RFC 4995 [ROHC]). To assist the reconstruction process, the AH/ESP sequence number SHOULD be used to identify segments that may have been subject Ertekin, et al. Expires June 7, 2010 [Page 9] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 to reordering. If reconstruction fails, the packet MUST be discarded. As stated in Section 3.2.1, if the ROHC integrity algorithm is used to verify the decompression of packet headers, this ICV is appended to the compressed packet. If ROHC segmentation is performed, the segmentation algorithm is executed on the compressed packet and the appended ICV. Note that the ICV is not appended to each ROHC segment. Under certain circumstances, IPsec implementations will not process (or receive) unprotected ICMP messages, or they will not have a Path MTU estimate value. In these cases, the IPsec implementation SHOULD NOT attempt to segment the ROHC-compressed packet, as it does not have full insight into the path MTU in the unprotected domain. 4.4. Nested IPComp and ROHCoIPsec Processing IPComp ([IPCOMP]) is another mechanism that can be implemented to reduce the size of an IP datagram. If IPComp and ROHCoIPsec are implemented in a nested fashion, the following steps MUST be followed for outbound and inbound packets. For outbound packets that are to be processed by IPcomp and ROHC: o The ICV is computed for the uncompressed packet, and the appropriate ROHC compression profile is applied to the packet o IPComp is applied, and the packet is sent to the IPsec process o The security protocol is applied to the packet Conversely, for inbound packets that are to be both ROHC- and IPcomp- decompressed: o A packet received on a ROHC-enabled SA is IPsec-processed o The datagram is decompressed based on the appropriate IPComp algorithm o The packet is sent to the ROHC module for header decompression and integrity verification 5. Security Considerations A ROHCoIPsec implementer should consider the strength of protection provided by the integrity check algorithm used to verify decompressed headers. Failure to implement a strong integrity check algorithm increases the probability for an invalidly decompressed packet to be forwarded by a ROHCoIPsec device into a protected domain. The implementation of ROHCoIPsec may increase the susceptibility for traffic flow analysis, where an attacker can identify new traffic Ertekin, et al. Expires June 7, 2010 [Page 10] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 flows by monitoring the relative size of the encrypted packets (i.e. a group of "long" packets, followed by a long series of "short" packets may indicate a new flow for some ROHCoIPsec implementations). To mitigate this concern, ROHC padding mechanisms may be used to arbitrarily add padding to transmitted packets to randomize packet sizes. This technique, however, reduces the overall efficiency benefit offered by header compression. 6. IANA Considerations IANA is requested to allocate one value within the "Protocol Numbers" registry [PROTOCOL] for "ROHC". This value will be used to indicate that the next level protocol header is a ROHC header. 7. Acknowledgments The authors would like to thank Mr. Sean O'Keeffe, Mr. James Kohler, Ms. Linda Noone of the Department of Defense, and Mr. A. Rich Espy of OPnet for their contributions and support for developing this document. The authors would also like to thank Mr. Yoav Nir, and Mr. Robert A Stangarone Jr.: both served as committed document reviewers for this specification. Finally, the authors would like to thank the following for their numerous reviews and comments to this document: o Mr. Magnus Westerlund o Dr. Stephen Kent o Mr. Lars-Erik Jonsson o Mr. Carl Knutsson o Mr. Pasi Eronen o Dr. Jonah Pezeshki o Mr. Tero Kivinen o Dr. Joseph Touch o Mr. Rohan Jasani Appendix A. ASN.1 representation for ROHCoIPsec This appendix is included as an additional way to describe the ROHCoIPsec parameters that are included in the IPsec SPD. It uses portions of the ASN.1 syntax provided in Appendix C of RFC 4301 [IPSEC]. In addition, several new structures are defined. Ertekin, et al. Expires June 7, 2010 [Page 11] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 This syntax has been successfully compiled. However, it is merely illustrative and need not be employed in an implementation to achieve compliance. The "Processing" data structure, defined in Appendix C of RFC 4301, is augmented to include a ROHC parameters element as follows: Processing ::= SEQUENCE { extSeqNum BOOLEAN, -- TRUE 64 bit counter, FALSE 32 bit seqOverflow BOOLEAN, -- TRUE rekey, FALSE terminate & audit fragCheck BOOLEAN, -- TRUE stateful fragment checking, -- FALSE no stateful fragment checking lifetime SALifetime, spi ManualSPI, algorithms ProcessingAlgs, tunnel TunnelOptions OPTIONAL, rohc [7] RohcParams OPTIONAL } The following data structures describe these ROHC parameters: RohcParams ::= SEQUENCE { rohcEnabled BOOLEAN, -- TRUE, hdr compr. is enabled -- FALSE, hdr compr. is disabled maxCID INTEGER (0..16383), mrru INTEGER, profiles RohcProfiles, rohcIntegAlg RohcIntegAlgs, rohcIntegICVLength INTEGER } RohcProfiles ::= SET OF RohcProfile RohcProfile ::= INTEGER { rohcv1-rtp (1), rohcv1-udp (2), rohcv1-esp (3), rohcv1-ip (4), rohcv1-tcp (6), rohcv1-rtp-udpLite (7), rohcv1-udpLite (8), rohcv2-rtp (257), rohcv2-udp (258), rohcv2-esp (259), rohcv2-ip (260), Ertekin, et al. Expires June 7, 2010 [Page 12] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 rohcv2-rtp-udpLite (263), rohcv2-udpLite (264) -- values taken from [ROHCPROF] } RohcIntegAlgs ::= SEQUENCE { algorithm RohcIntegAlgType, parameters ANY -- DEFINED BY algorithm -- OPTIONAL } RohcIntegAlgType ::= INTEGER { none (0), auth-HMAC-MD5-96 (1), auth-HMAC-SHA1-96 (2), auth-DES-MAC (3), auth-KPDK-MD5 (4), auth-AES-XCBC-96 (5), auth-HMAC-MD5-128 (6), auth-HMAC-SHA1-160 (7), auth-AES-CMAC-96 (8), auth-AES-128-GMAC (9), auth-AES-192-GMAC (10), auth-AES-256-GMAC (11), auth-HMAC-SHA2-256-128 (12), auth-HMAC-SHA2-384-192 (13), auth-HMAC-SHA2-512-256 (14) -- tbd (15..65535) -- values taken from "Transform Type 3 - Integrity -- Algorithm Transform IDs" at [IKEV2-PARA] } 8. References 8.1. Normative References [IPSEC] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, December 2005. [ROHC] Jonsson, L-E., Pelletier, G., and K. Sandlund, "The RObust Header Compression (ROHC) Framework", RFC 4995, July 2007. [IPCOMP] Shacham, A., Monsour, R., Pereira, and Thomas, "IP Payload Compression Protocol (IPComp)", RFC 3173, September 2001. Ertekin, et al. Expires June 7, 2010 [Page 13] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 [BRA97] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997. [ROHCV2] Pelletier, G. and K. Sandlund, "RObust Header Compression Version 2 (ROHCv2): Profiles for RTP, UDP, IP, ESP and UDP-Lite", RFC 5225. [IKEV2] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol", RFC 4306, December 2005. [IKEV2EXT] Ertekin, et al., "Extensions to IKEv2 to Support Robust Header Compression over IPsec (ROHCoIPsec)", work in progress , December 2009. [AH] Kent, S., "IP Authentication Header", RFC 4302, December 2005. [ESP] Kent, S., "IP Encapsulating Security Payload (ESP)", RFC 4303, December 2005. 8.2. Informative References [ROHCOIPSEC] Ertekin, E., Jasani, R., Christou, C., and C. Bormann, "Integration of Header Compression over IPsec Security Associations", work in progress , December 2009. [ROHCPROF] "RObust Header Compression (ROHC) Profile Identifiers", www.iana.org/assignments/rohc-pro-ids , May 2008. [CRYPTO-ALG] Manral, V., "Cryptographic Algorithm Implementation Requirements for Encapsulating Security Payload (ESP) and Authentication Header (AH)", RFC 4835, April 2007. [ROHC-TERM] Jonsson, L-E., "Robust Header Compression (ROHC): Terminology and Channel Mapping Examples", RFC 3759, April 2004. [PROTOCOL] IANA, ""Assigned Internet Protocol Numbers", IANA registry at: http://www.iana.org/assignments/protocol-numbers". [IKEV2-PARA] IANA, "IKEv2 Parameters, Ertekin, et al. Expires June 7, 2010 [Page 14] Internet-Draft IPsec Extensions to Support ROHCoIPsec December 2009 http://www.iana.org/assignments/ikev2-parameters", November 2009. Authors' Addresses Emre Ertekin Booz Allen Hamilton 5220 Pacific Concourse Drive, Suite 200 Los Angeles, CA 90045 US Email: ertekin_emre@bah.com Chris Christou Booz Allen Hamilton 13200 Woodland Park Dr. Herndon, VA 20171 US Email: christou_chris@bah.com Carsten Bormann Universitaet Bremen TZI Postfach 330440 Bremen D-28334 Germany Email: cabo@tzi.org Ertekin, et al. Expires June 7, 2010 [Page 15]