Network Working Group E. Ertekin
Internet-Draft C. Christou
Expires: August 28, 2006 R. Jasani
Booz Allen Hamilton
February 24, 2006
Integration of Header Compression over IPsec Security Associations
draft-ietf-rohc-hcoipsec-01
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Copyright (C) The Internet Society (2006).
Abstract
Internet Protocol security mechanisms, such as IP Security (IPsec)
[IPSEC], provides various security services for IP traffic. However,
the benefits offered by IPsec come at the cost of increased overhead.
This document identifies a set of work items that need to be
completed to achieve the integration of header compression (HC) over
IPsec (HCoIPsec). HCoIPsec proposes to reduce the amount of packet
overhead associated with the transmission of traffic over tunnel mode
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security associations.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Problem Statement: Packet Overhead Associated with IPsec
Tunnel-Mode SAs . . . . . . . . . . . . . . . . . . . . . . . 4
5. The Header Compression Solution . . . . . . . . . . . . . . . 5
6. Integration Methodology . . . . . . . . . . . . . . . . . . . 6
6.1. Work Assumptions . . . . . . . . . . . . . . . . . . . . . 6
6.2. Work Items . . . . . . . . . . . . . . . . . . . . . . . . 7
6.2.1. Header Compression Scheme-Specific Extensions . . . . 8
6.2.2. Initialization and Negotiation of Header
Compression Channel . . . . . . . . . . . . . . . . . 8
6.2.3. Encapsulation and Identification of Header
Compressed Packets . . . . . . . . . . . . . . . . . . 9
7. Candidate Compression Schemes . . . . . . . . . . . . . . . . 9
8. Example Operation . . . . . . . . . . . . . . . . . . . . . . 10
9. Future Work Items . . . . . . . . . . . . . . . . . . . . . . 12
9.1. HCoIPsec Transport Mode SAs . . . . . . . . . . . . . . . 12
10. Security Considerations . . . . . . . . . . . . . . . . . . . 13
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
13.1. Normative References . . . . . . . . . . . . . . . . . . . 14
13.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
Intellectual Property and Copyright Statements . . . . . . . . . . 17
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1. Introduction
This document identifies a set of work items that need to be
completed in order to achieve the integration of header compression
(HC) over IPsec Security Associations (SAs) operating in tunnel mode.
The goal of integrating HC with IPsec is to reduce the protocol
overhead associated with packets traversing between IPsec SA
endpoints. This goal can be achieved by compressing the upper layer
protocols (e.g., RTP/UDP and TCP) and the inner IP header of packets,
at the ingress of the IPsec tunnel, and decompression at the egress.
To accomplish HCoIPsec, this document proposes the use of Internet
Protocol Header Compression [IPHC], Compressed Real Time Protocol
[CRTP], Enhanced Compressed Real Time Protocol [ECRTP], and Robust
Header Compression [ROHC], to compress the inner headers of IP
packets traversing within an IPsec tunnel. However, since these HC
schemes operate on a hop-by-hop basis, several extensions need to be
defined. This document details a technique which will enable these
traditional hop-by-hop HC schemes to be extended, and operate between
IPsec SA endpoints.
Currently, HCoIPsec primarily targets the application of HC to tunnel
mode SAs as opposed to transport mode SAs. Transport mode SAs
encrypt/authenticate only the payload of an IP packet, leaving the
original IP header untouched. Intermediate routers subsequently use
the original IP header to route the packet to a decryption device.
Therefore, if HC were extended to operate between IPsec transport-
mode SA endpoints, (de)compression functionality can be applied only
to the transport layer headers and not the IP header. Since
compression of transport layer headers alone does not provide
substantial efficiency gains, it is not integrated into HCoIPsec.
2. Audience
The target audience includes those who are involved with the design
and development of HC schemes, and IPsec mechanisms. Since
traditional IETF HC schemes are designed to operate on a hop-by-hop
basis, they need to be modified to operate over IPsec SAs.
Therefore, the authors target various HC and IPsec communities who
may consider extending hop-by-hop HC schemes and IPsec protocols to
meet the requirements put forward in this document. Finally, this
document is directed towards vendors developing IPsec devices which
will be deployed in bandwidth-constrained, IP networks.
3. Terminology
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Terminology specific to discussion of HCoIPsec is introduced in this
section.
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.
Compressed Traffic
Traffic that is processed by the compressor (compressed) using one
of the existing profiles. Note: This includes packets that might
be compressed using an "uncompressed" profile.
Uncompressed Traffic
Traffic that is not processed by the compressor. Instead, this
type of traffic is bypassed by the HC process.
HC Process
Generic reference to either the compressor, decompressor, and any
supporting header compression (HC) components.
IPsec Process
Generic reference to Internet Protocol Security (IPsec) process
[IPSEC].
4. Problem Statement: Packet Overhead Associated with IPsec Tunnel-Mode
SAs
IPsec mechanisms provide various security services for IP-based
networks. For example, ESP offers data origin authentication,
connectionless integrity, anti-replay service, and limited traffic
flow confidentiality [ESP].
The benefits of IPsec mechanisms come at the cost of increased per-
packet overhead in the network. For example, traffic flow
confidentiality, which is generally implemented at security gateways,
requires the tunneling of IP packets between the IPsec devices.
IPsec tunnels may mask the source-destination patterns that an
intruder may ascertain, but the benefit comes at the cost of extra
per-packet overhead. An ESP tunnel mode SA applied to an IPv6 flow
results in at least 50 bytes of additional overhead per packet. This
additional overhead may be undesirable for many bandwidth-constrained
wireless and/or Satellite Communications (SATCOM) networks, as these
types of infrastructure are not overprovisioned. Consequently, the
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additional overhead incurred in an encryption-based environment may
hinder the efficient utilization of bandwidth.
In bandwidth-constrained, high bit error rate (BER) networks, IP
Packet Loss Ratio (IPLR) can severely degrade end-host application
performance. The traditional means for combating IPLR on high BER
links has been Error Correction Codes (ECC). In addition, end-host
applications may not have the luxury of sending packets with large
payloads. This is due to the fact that large packets traversing high
BER links result in high IP Packet Loss Ratio (IPLR). To reduce
IPLR, end-host devices may reduce the size of packet payloads, which
decreases the probability that a packet is lost due to a bit error.
Reducing the size of packet payloads, however, increases the amount
of overhead transmitted between the two end hosts. Moreover, if
these packets traverse over an IPsec tunnel mode SA, the amount of
overhead is further magnified. A mechanism is needed to reduce the
overhead associated with such flows.
5. The Header Compression Solution
IP HC schemes provide one mechanism to reduce packet overhead in an
IP network. Schemes such as IPHC, CRTP, ECRTP and ROHC exploit
inter-packet redundancies of network and transport-layer header
fields of a flow to reduce the amount of redundant header data
transmitted between two nodes.
To apply HC schemes over IPsec SAs, several extensions to the
existing schemes need to be developed. Existing HC schemes such as
IPHC, CRTP, ECRTP and ROHC are designed to compress headers on a hop-
by-hop basis. IPsec SAs, however, may be instantiated between IPsec
devices functioning as gateways, with multiple intermediary nodes
between the IPsec gateways. Therefore, to fully integrate HC with
IPsec SAs, traditional hop-by-hop schemes need to be extended to
operate between IPsec SA endpoints.
The migration of traditional hop-by-hop HC schemes over IPsec SAs is
simple, as SA endpoints provide source/destination pairs where
(de)compression operations can take place. Compression in such a
manner offers both a reduction of per-packet protocol overhead
between the two SA endpoints, and does not require compression and
decompression cycles at the intermediate network nodes between the
IPsec devices. Since HC schemes will now essentially operate over
multiple hops, it is imperative that the performance of the HC
schemes is not severely impacted due to increased packet reordering
and/or IPLR events between the compressor and decompressor. It
should be noted that the notion of extending hop-by-hop HC schemes to
operate over multiple hops is not new, as the HCoIPsec effort
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parallels other efforts such as ECRTP over MPLS [HCOMPLS].
Using the proposed architecture, outbound IP traffic processing at an
IPsec device is augmented to compress appropriate packet headers, and
subsequently encrypt and/or integrity-protect the packet. For tunnel
mode SAs, compression may be applied to the transport layer protocol
and the inner IP header.
Inbound IP traffic processing at an IPsec device is modified in a
similar fashion. For inbound packets, an IPsec device must first
decrypt and/or integrity-check the packet. Then, the IPsec device
implicitly determines whether the packet was received on a HC-enabled
SA. If the packet was received over a HC-enabled SA, the
decompression function takes place.
Note: Compression of inner headers is completely independent from
compression of the outer (e.g., ESP/IP) headers. Intermediate
network nodes between IPsec endpoints may also compress the outer
ESP/IP headers. Current HC schemes such as ROHC and IPHC contain
the ability to compress these ESP/IP headers. Further discussion
of hop-by-hop compression of the outer ESP/IP headers is out of
the scope of this document.
If IPsec NULL encryption is applied on packets, HC schemes may still
be applied on the inner headers at the IPsec SA endpoints. Inbound
and outbound packets are processed as described previously. In
scenarios where NULL-encrypted packets traverse intermediate nodes
between the IPsec SA endpoints, the intermediary nodes must not
attempt to (de)compress the inner IP and/or transport layer headers
on a hop-by-hop basis.
6. Integration Methodology
The goal for HCoIPsec is to provide more efficient transport of IP
packets between source and destination IPsec devices, via tunnel mode
SAs, without compromising security services offered by IPsec.
With this general goal in mind, Section 5.1 defines a set of work
assumptions to guide the direction of the HCoIPsec solution. Based
on these work assumptions, Section 5.2 defines work items which need
to be addressed to achieve the HCoIPsec solution.
6.1. Work Assumptions
a. HCoIPsec must use existing HC protocols (e.g., IPHC, CRTP, ECRTP,
ROHC) to reduce the amount of overhead associated with packets
traversing an IPsec tunnel-mode SA.
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b. HCoIPsec must execute (de)compression operations at IPsec SA
endpoints, and must not perform (de)compression cycles at
intermediate nodes between IPsec devices.
c. HCoIPsec must be independent of the underlying link layer framing
protocol (e.g., PPP).
d. HCoIPsec must allow each SA to constitute a HC channel, enabling
each SA to have its own CID space.
e. An SA with HC enabled should not deliver a larger number of
erroneous packets than the same SA with HC disabled.
The motivation behind (c) comes from the realization that an SA may
traverse multiple links, employing various framing protocols, and
that the set of links (and thus framing protocols) may change during
the lifetime of an SA. Therefore, link layer dependencies exhibited
by traditional hop-by-hop HC schemes cannot be used in the HCoIPsec
solution.
6.2. Work Items
This section identifies several work items that need to be addressed
to achieve HCoIPsec. The first work item encompasses the HC scheme-
specific extensions needed to ensure that traditional hop-by-hop HC
schemes will operate efficiently over IPsec SA endpoints:
a. Header Compression Scheme-Specific Extensions: Any modifications
needed to be made to existing HC schemes, which will facilitate
their operation over IPsec SAs. (Section 5.2.1)
Hop-by-hop HC schemes use the underlying link layer (e.g., PPP) to
negotiate the HC channel parameters and to indicate the type of
compressed packet the data-link layer frame is encapsulating. To
remove HC scheme dependencies on the underlying link layer, two
additional work items are proposed:
b. Initialization and Negotiation of the Header Compression Channel:
Mechanisms needed to initialize a HC channel and negotiate HC
scheme parameters prior to operation. (Section 5.2.2)
c. Encapsulation and Identification of Header Compressed Packets:
Mechanisms that encapsulate and identify compressed header
packets, as well as how these mechanisms will operate. (Section
5.2.3)
Note: (c) is still being discussed within the community and is
subject to change. More information about (c) can be found in the
"Alternatives to Achieving HCoIPsec" internet-draft, a document being
used to help resolve HCoIPsec discussions and issues in order to
stabilize the HCoIPsec draft.
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6.2.1. Header Compression Scheme-Specific Extensions
a. HCoIPsec should minimize HC scheme performance degradation due to
increased delays, packet loss, jitter, and reordering events
between compressor and decompressor.
b. HCoIPsec should minimize the amount of HC signaling between
compressor and decompressor.
c. HCoIPsec should support bi-directional communications
functionality, used by certain HC schemes (e.g. ROHC bi-
directional mode).
The intention of (b) is to indicate that if a feedback channel from
the decompressor to the compressor is not used sparingly, then the
overall gains from HCoIPsec can be significantly reduced (even more
so than hop-by-hop HC). For example, take the case where ROHC in bi-
directional reliable mode is instantiated over an IPsec tunnel mode
SA. Any feedback sent from the decompressor to the compressor may be
tunneled, and therefore, the additional overhead incurred by
tunneling the feedback will reduce the overall benefits of HC.
Note that if a HCoIPsec session requires bidirectional communication
between the compressor and the decompressor (e.g., a ROHC session
operating in bidirectional-reliable mode, or bidirectional-optimistic
mode, or ECRTP and CONTEXT_STATE packets), this may pose an issue,
given that SAs are unidirectional, and that HCoIPsec defines a HC
context to be specific to a given SA. Any feedback packet
communicated from the HCoIPsec decompressor to the HCoIPsec
compressor is over a separate SA back to the original IPsec device.
To identify the stale context, the feedback packet must contain the
context ID as well as an indication of the SA that the decompressor
is associated to. This poses a problem for current HC algorithm
feedback packets, which are not structured to carry the additional SA
indication information. For example, current ECRTP feedback
mechanisms (e.g., CONTEXT_STATE) only list the CIDs for which
synchronization has been lost. If a bidirectional HC algorithm is to
be integrated with IPsec, additional HC scheme-specific extensions
must be defined to resolve this issue.
6.2.2. Initialization and Negotiation of Header Compression Channel
Initialization of the HC channel will be achieved manually (i.e.,
administratively configured for manual SAs), or will be performed by
IPsec SA establishment protocols, e.g. IKE. During SA
initialization, the type of HC scheme configured for the SA, as well
as the HC scheme's channel parameters will be identified.
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a. HCoIPsec may leverage IKE, IKEv2 to negotiate HC channel
parameters (e.g., for ROHC, IKE(v2) shall initialize PROFILES,
MAX_CID, MAX_HEADER, MRRU).
b. HCoIPsec must allow packets with uncompressed headers and packets
with compressed headers to traverse a single SA. "Packets with
compressed headers" refer to packets which are selected to an HC-
enabled SA, are passed to the compressor, and are actually
compressed; "packets with uncompressed headers" refer to packets
which are selected to an HC-enabled SA, are passed to the
compressor, and are not "compressed" (e.g., ROHC compressor
processes a packet with the uncompressed profile).
Note: (b) is necessary in situations where a compressor--can not
compress a flow (e.g., a compressor supports strictly n compressed
flows, and can not compress the n+1 flow that arrives).
Note: (b) is still being discussed within the community and is
subject to change. More information about (b) can be found in the
"Alternatives to Achieving HCoIPsec" internet-draft, a document being
used to help resolve HCoIPsec discussions and issues in order to
stabilize the HCoIPsec draft.
6.2.3. Encapsulation and Identification of Header Compressed Packets
For indication purposes, a one-byte header may be added to the
compressed packet; this field will help the decompressor identify how
to process the compressed packet. This one-byte header is only
relevant to the HC compression and decompression processes, and is
not used by IPsec..
a. HCoIPsec must indicate the type of compressed packet (e.g., for
ECRTP, COMPRESSED_RTP_8, COMPRESSED_RTP_16, CONTEXT_STATE, etc.)
on a per packet basis.
Note that ROHC indicates its own packet type within the protocol, and
does not require a new one-byte header to indicate the type of
compressed packet.
Note: Alternatives to using a "one-byte header" are still being
discussed within the community, thus this section may change. More
information can be found in the "Alternatives to Achieving HCoIPsec"
internet-draft, a document being used to help resolve HCoIPsec
discussions and issues in order to stabilize the HCoIPsec draft.
7. Candidate Compression Schemes
IPHC can be used to compress TCP/IP headers for tunnel mode SAs.
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IPHC, however, has been identified as a HC scheme that performs
poorly over long round trip time (RTT), high BER links [ROHC].
Extensions to IPHC to compress TCP/IP headers over an IPsec SA need
to take into consideration longer RTTs, increased potential for
packet reordering and IPLR between the compressor and decompressor.
CRTP can be used to compress RTP/UDP/IP headers for tunnel mode SAs.
CRTP, however, has also been identified as a HC scheme that performs
poorly over long RTT, high BER links [CRTPE]. Recent modifications
to the CRTP scheme, such as ECRTP, enables the CRTP HC scheme to
tolerate long RTTs, packet loss, between compressor and decompressor.
The reordering tolerance of ECRTP, however, needs to be evaluated, as
detailed in [ECRTPE]. Such implementation aspects should be taken
into consideration when extending ECRTP to operate between IPsec SA
endpoints.
ROHC, as defined in RFC 3095, provides a robust HC scheme that is
designed for high BER, long RTT links. This makes ROHC another
candidate header scheme to operate over IPsec tunnels. ROHC can be
used to compress not only RTP/UDP/IP headers, but also TCP/IP
headers, as defined in [ROHCTCP]. Similar to CRTP and IPHC, ROHC has
been identified as vulnerable to packet reordering events between the
compressor and decompressor[ROHCE]. Recent work [ROHCWEXT] suggests
that the implementation aspects of ROHC can be modified to achieve
tolerance to packet reordering events. Such implementation aspects
should be taken into consideration when extending ROHC to operate
between IPsec SA endpoints.
The ability to tolerate these network characteristics is a necessity
for any HCoIPsec scheme, and will be a factor in determining how
efficiently the HC scheme operates over the IPsec tunnel-mode SAs.
8. Example Operation
The basic operation of the HCoIPsec protocol is detailed in the
following example. Assume there are two IPsec devices operating as
security gateways. HCoIPsec leverages an SA establishment protocol
(e.g., IKE, IKEv2) to negotiate the HC scheme, and channel
parameters. For example, the MAX_CID, MRRU, MAX_HEADER, and PROFILES
parameters will be negotiated for each IPsec SA which is capable of
ROHC. For an IPsec SA that is ECRTP-enabled, channel parameters
including F_MAX_PERIOD, F_MAX_TIME, and the ECRTP Compression
Suboption will be initialized. For the following example, assume
that a SA has been established.
Outbound packet processing is as follows. The packet is initially
processed as described in Steps 1-2, Section 5.1 of RFC 4301. The
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SPD cache entry then maps the packet to a given SAD entry, which
indicates the HC protocol enabled on the SA (in addition to mode,
cryptographic algorithms, keys, etc.). If the SAD entry indicates
that compression is disabled, then standard IPsec processing ensues,
as described in Steps 3-4, Section 5.1 of RFC 4301. If the SAD entry
indicates that compression is enabled, the packet must be handed to
the appropriate compressor, which executes the compression process.
After the packet's header is compressed, the packet resumes IPsec
processing as described in Step 3a, where standard IPsec ESP
processing ensues (including packet encryption according to the SAD
entry parameters, packet encapsulation with the outer ESP/IP header)
and is subsequently passed to the outbound forwarding function, as
described in Step 4 of RFC 4301.
Inbound packet processing is as follows. The packet is initially
processed as described in Steps 1-3, Section 5.2 of RFC 4301;
subsequently (using the SAD entry selected in Step 3a), ESP
processing is applied. Based on information retrieved from the SAD
entry, it can also be determined whether traffic traversing the SA is
compressed or not compressed. If the SAD entry indicates that
compression is not enabled on the SA, then standard IPsec processing
of the packet ensues, as described in Step 4, Section 5.2 of RFC
4301. If compression is enabled on the SA, the packet is handed to
the decompressor for "decompression". Once the packet is
decompressed, the processing as described in Step 4, Section 5.2 of
RFC 4301 resumes (specifically "Then match the packet against the
inbound selectors identified by the SAD...").
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Figure 1 depicts the basic function of HCoIPsec:
-- -- -- -- -- -- -- -- -- --
|ESP Tunnel Mode Security Association|
| |
| |
V V
+--------------+ +--------------+
| IPsec Device | +--+ +--+ | IPsec Device |
| | | | | | | |
+---| Compressor |-->|R1|-->|R2|-->| Decompressor |---+
| | | | | | | | | |
| +--------------+ +--+ +--+ +--------------+ |
| | | |
| |-----------------| |
| | |
| | |
V V V
+-----------------+ +-----------------------+ +-----------------+
| | | | | | | | | | | |
| | UDP | | | | E | ------------- | | | UDP | |
|IP | / |Payload| |IP | S | |CID|Payload| | |IP | / |Payload|
| | RTP | | | | P | ------------- | | | RTP | |
| | | | | | | | | | | |
+-----------------+ +-----------------------+ +-----------------+
| |
|---ENCRYPTED---|
| |
Figure 1: Example operation of HCoIPsec.
In the example scenario, note that the inbound and outbound packets
are first mapped to an SA, and then subsequently mapped to a CID.
This implies that the scope of each CID is contained within each SA.
A CID value of 1 can be associated with multiple SAs; however, the
context state information for CID 1 cannot be shared over multiple
SAs.
9. Future Work Items
9.1. HCoIPsec Transport Mode SAs
Many of the current HC profiles look to simultaneously compress
network and transport layer headers of IP packets. This makes the
extension of traditional HC schemes over transport-mode SAs more
difficult. For the application of HC over transport mode SAs,
traditional HC schemes may need to be extended to operate strictly on
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layer 4 (e.g., TCP, and/or RTP/UDP) headers. The specification for
HCoIPsec transport mode SAs is left for further study.
10. Security Considerations
A malfunctioning header compressor (i.e., the compressor located at
the ingress of the IPsec tunnel; used during outbound processing) has
the ability to send packets to the decompressor (i.e., the
decompressor located at the egress of the IPsec tunnel; used during
inbound processing) that do not match the original packets emitted
from the end-hosts. In such a scenario, the invalid packets will
pass through inbound IPsec processing, and will subsequently be
validly decompressed.
Furthermore, an intruder who has the ability to arbitrarily inject
packets between SA endpoints, and addresses these malicious packets
to the encryption/decryption devices, has the ability to cause
context corruption between the compressor and decompressor processes
instantiated within the IPsec device (if the malicious packet passes
through the decryption process). Such a scenario will result in a
decreased efficiency between compressor and decompressor, and
furthermore, may result in Denial of Service, as the decompression of
a significant number of invalid packets may drain the resources of an
IPsec device.
Note: It should be noted, however, that these security issues are
a direct result of IPsec vulnerabilities.
11. IANA Considerations
None.
12. Acknowledgments
The authors would like to thank Mr. Sean O'Keeffe, Mr. James Kohler,
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. Jan Vilhuber, Mr. Dan Wing, of Cisco
Systems, Mr. Lars-Erik Jonsson and Mr. Kristopher Sandlund of
Ericsson for their valuable contributions to this document. The
authors would also like to thank Ms. Renee Esposito, Mr. Etzel
Brower, Mr. Jigar Amroliwala, and Mr. Dwayne Corbin of Booz Allen
Hamilton for their assistance in completing this work.
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13. References
13.1. Normative References
[IPSEC] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, December 2005.
[IPHC] Nordgren, M., Pink, B., and S. Pink, "IP Header
Compression", RFC 2507, February 1999.
[CRTP] Casner, S. and V. Jacobson, "Compressing IP/UDP/RTP
Headers for Low-Speed Serial Links", RFC 2508,
February 1999.
[ECRTP] Koren, T. and et. al., "Compressing IP/UDP/RTP Headers on
Links with High Delay, Packet Loss, and Reordering",
RFC 3545, July 2003.
[ROHC] Bormann, C., Burmeister, C., Degermark, M., Fukushima, H.,
Hannu, H., Jonsson, L., Hakenberg, R., Koren, T., Le, K.,
Liu, Z., Martensson, A., Miyazaki, A., Svanbro, K.,
Wiebke, T., Yoshimura, T., and H. Zheng, "RObust Header
Compression (ROHC): Framework and four profiles: RTP, UDP,
ESP, and uncompressed", RFC 3095, July 2001.
[ECRTPE] Knutsson, C., "Evaluation and Implemenation[sic] of Header
Compression Algorithm ECRTP", November 2004.
[ROHCTCP] Pelletier, G. and et. al, "Robust Header Compression: A
Profile For TCP/IP (ROHC-TCP)", work in progress ,
January 2006.
[ROHCWEXT]
Pelletier, G. and et. al, "ROHC over Channels That Can
Reorder Packets", RFC 4224, January 2006.
13.2. Informative References
[ESP] Kent, S., "IP Encapsulating Security Payload", RFC 4303,
December 2005.
[HCOMPLS] Ash, J. and et. al, "Protocol Extensions for Header
Compression over MPLS", April 2005.
[CRTPE] Degermark, M., Hannu, H., Jonsson, L., and K. Svanbro,
"Evaluation of CRTP Performance over Cellular Radio
Networks", IEEE Personal Communication Magazine , Volume
7, number 4, pp. 20-25, August 2000.
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[ROHCE] Ash, J. and et. al, "Requirements for ECRTP over MPLS",
RFC 4247, November 2005.
[AAL2] ITU-T, "B-ISDN ATM Adaptation layer specification: Type 2
AAL", I.363.2 , September 1997.
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Authors' Addresses
Emre Ertekin
Booz Allen Hamilton
13200 Woodland Park Dr.
Herndon, VA 20171
US
Email: ertekin_emre@bah.com
Chris Christou
Booz Allen Hamilton
13200 Woodland Park Dr.
Herndon, VA 20171
US
Email: christou_chris@bah.com
Rohan Jasani
Booz Allen Hamilton
13200 Woodland Park Dr.
Herndon, VA 20171
US
Email: jasani_rohan@bah.com
Ertekin, et al. Expires August 28, 2006 [Page 16]
Internet-Draft Integration of HC over IPsec SAs February 2006
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Ertekin, et al. Expires August 28, 2006 [Page 17]
