| Rfc | 5856 |
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| Title | Integration of Robust Header Compression over IPsec Security
Associations |
|---|
| Author | E. Ertekin, R. Jasani, C. Christou, C. Bormann |
|---|
| Date | May
2010 |
|---|
| Format: | TXT, HTML |
|---|
| Status: | INFORMATIONAL |
|---|
|
Internet Engineering Task Force (IETF) E. Ertekin
Request for Comments: 5856 R. Jasani
Category: Informational C. Christou
ISSN: 2070-1721 Booz Allen Hamilton
C. Bormann
Universitaet Bremen TZI
May 2010
Integration of Robust Header Compression over
IPsec Security Associations
Abstract
IP Security (IPsec) provides various security services for IP
traffic. However, the benefits of IPsec come at the cost of
increased overhead. This document outlines a framework for
integrating Robust Header Compression (ROHC) over IPsec (ROHCoIPsec).
By compressing the inner headers of IP packets, ROHCoIPsec proposes
to reduce the amount of overhead associated with the transmission of
traffic over IPsec Security Associations (SAs).
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It has been approved for publication by the Internet
Engineering Steering Group (IESG). Not all documents approved by the
IESG are a candidate for any level of Internet Standard; see Section
2 of RFC 5741.
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/rfc5856.
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Table of Contents
1. Introduction ....................................................3
2. Audience ........................................................3
3. Terminology .....................................................3
4. Problem Statement: IPsec Packet Overhead ........................4
5. Overview of the ROHCoIPsec Framework ............................5
5.1. ROHCoIPsec Assumptions .....................................5
5.2. Summary of the ROHCoIPsec Framework ........................5
6. Details of the ROHCoIPsec Framework .............................7
6.1. ROHC and IPsec Integration .................................7
6.1.1. Header Compression Protocol Considerations ..........9
6.1.2. Initialization and Negotiation of the ROHC Channel ..9
6.1.3. Encapsulation and Identification of Header
Compressed Packets .................................10
6.1.4. Motivation for the ROHC ICV ........................11
6.1.5. Path MTU Considerations ............................11
6.2. ROHCoIPsec Framework Summary ..............................12
7. Security Considerations ........................................12
8. IANA Considerations ............................................12
9. Acknowledgments ................................................13
10. Informative References ........................................14
1. Introduction
This document outlines a framework for integrating ROHC [ROHC] over
IPsec [IPSEC] (ROHCoIPsec). The goal of ROHCoIPsec is to reduce the
protocol overhead associated with packets traversing between IPsec SA
endpoints. This can be achieved by compressing the transport layer
header (e.g., UDP, TCP, etc.) and inner IP header of packets at the
ingress of the IPsec tunnel, and decompressing these headers at the
egress.
For ROHCoIPsec, this document assumes that ROHC will be used to
compress the inner headers of IP packets traversing an IPsec tunnel.
However, since current specifications for ROHC detail its operation
on a hop-by-hop basis, it requires extensions to enable its operation
over IPsec SAs. This document outlines a framework for extending the
usage of ROHC to operate at IPsec SA endpoints.
ROHCoIPsec targets the application of ROHC to tunnel mode SAs.
Transport mode SAs only protect the payload of an IP packet, leaving
the IP header untouched. Intermediate routers subsequently use this
IP header to route the packet to a decryption device. Therefore, if
ROHC is to operate over IPsec transport-mode SAs, (de)compression
functionality can only be applied to the transport layer headers, and
not to the IP header. Because current ROHC specifications do not
include support for the compression of transport layer headers alone,
the ROHCoIPsec framework outlined by this document describes the
application of ROHC to tunnel mode SAs.
2. Audience
The authors target members of both the ROHC and IPsec communities who
may consider extending the ROHC and IPsec protocols to meet the
requirements put forth in this document. In addition, this document
is directed towards vendors developing IPsec devices that will be
deployed in bandwidth-constrained IP networks.
3. Terminology
ROHC Process
Generic reference to a ROHC instance (as defined in RFC 3759
[ROHC-TERM]) or any supporting ROHC components.
Compressed Traffic
Traffic that is processed through the ROHC compressor and
decompressor instances. Packet headers are compressed and
decompressed using a specific header compression profile.
Uncompressed Traffic
Traffic that is not processed by the ROHC compressor instance.
Instead, this type of traffic bypasses the ROHC process.
IPsec Process
Generic reference to the Internet Protocol Security (IPsec)
process.
Next Header
Refers to the Protocol (IPv4) or Next Header (IPv6, Extension)
field.
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].
4. Problem Statement: IPsec Packet Overhead
IPsec mechanisms provide various security services for IP networks.
However, the benefits of IPsec come at the cost of increased per-
packet overhead. For example, traffic flow confidentiality
(generally leveraged at security gateways) requires the tunneling of
IP packets between IPsec implementations. Although these IPsec
tunnels will effectively mask the source-destination patterns that an
intruder can ascertain, tunneling comes at the cost of increased
packet overhead. Specifically, an Encapsulating Security Payload
(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 networks, as these types of infrastructure
are not overprovisioned. ROHC applied on a per-hop basis over
bandwidth-constrained links will also suffer from reduced performance
when encryption is used on the tunneled header, since encrypted
headers cannot be compressed. Consequently, the additional overhead
incurred by an IPsec tunnel may result in the inefficient utilization
of bandwidth.
Packet overhead is particularly significant for traffic profiles
characterized by small packet payloads (e.g., various voice codecs).
If these small packets are afforded the security services of an IPsec
tunnel mode SA, the amount of per-packet overhead is increased.
Thus, a mechanism is needed to reduce the overhead associated with
such flows.
5. Overview of the ROHCoIPsec Framework
5.1. ROHCoIPsec Assumptions
The goal of ROHCoIPsec is to provide efficient transport of IP
packets between IPsec devices without compromising the security
services offered by IPsec. The ROHCoIPsec framework has been
developed based on the following assumptions:
o ROHC will be leveraged to reduce the amount of overhead associated
with unicast IP packets traversing an IPsec SA.
o ROHC will be instantiated at the IPsec SA endpoints, and it will
be applied on a per-SA basis.
o Once the decompression operation completes, decompressed packet
headers will be identical to the original packet headers before
compression.
5.2. Summary of the ROHCoIPsec Framework
ROHC reduces packet overhead in a network by exploiting intra- and
inter-packet redundancies of network and transport-layer header
fields of a flow.
Current ROHC protocol specifications compress packet headers on a
hop-by-hop basis. However, IPsec SAs are instantiated between two
IPsec endpoints. Therefore, various extensions to both ROHC and
IPsec need to be defined to ensure the successful operation of the
ROHC protocol at IPsec SA endpoints.
The specification of ROHC over IPsec SAs is straightforward, since SA
endpoints provide source/destination pairs where (de)compression
operations can take place. Compression of the inner IP and upper
layer protocol headers in such a manner offers a reduction of packet
overhead between the two SA endpoints. Since ROHC will now operate
between IPsec endpoints (over multiple intermediate nodes that are
transparent to an IPsec SA), it is imperative to ensure that its
performance will not be severely impacted due to increased packet
reordering and/or packet loss between the compressor and
decompressor.
In addition, ROHC can no longer rely on the underlying link layer for
ROHC channel parameter configuration and packet identification. The
ROHCoIPsec framework proposes that ROHC channel parameter
configuration is accomplished by an SA management protocol (e.g.,
Internet Key Exchange Protocol version 2 (IKEv2) [IKEV2]), while
identification of compressed header packets is achieved through the
Next Header field of the security protocol (e.g., Authentication
Header (AH) [AH], ESP [ESP]) header.
Using the ROHCoIPsec framework proposed below, outbound and inbound
IP traffic processing at an IPsec device needs to be modified. For
an outbound packet, a ROHCoIPsec implementation will 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 and the inner IP headers. For inbound
packets, an IPsec device must first decrypt and/or integrity check
the packet. Then, decompression of the inner packet headers is
performed. After decompression, the packet is checked against the
access controls imposed on all inbound traffic associated with the SA
(as specified in RFC 4301 [IPSEC]).
Note: Compression of inner headers is independent from compression
of the security protocol (e.g., ESP) and outer IP headers. ROHC
profiles have been defined to allow for the compression of the
security protocol and the outer IP header on a hop-by-hop basis.
The applicability of ROHCoIPsec and hop-by-hop ROHC on an IPv4
ESP-processed packet [ESP] is shown below in Figure 1.
-----------------------------------------------------------
IPv4 | new IP hdr | | orig IP hdr | | | ESP | ESP|
|(any options)| ESP | (any options) |TCP|Data|Trailer| ICV|
-----------------------------------------------------------
|<-------(1)------->|<------(2)-------->|
(1) Compressed hop-by-hop by the ROHC [ROHC]
ESP/IP profile
(2) Compressed end-to-end by the ROHCoIPsec [IPSEC-ROHC]
TCP/IP profile
Figure 1. Applicability of hop-by-hop ROHC and ROHCoIPsec on an
IPv4 ESP-processed packet.
If IPsec NULL encryption is applied to packets, ROHC may still be
used to compress the inner headers at IPsec SA endpoints. However,
compression of these inner headers may pose challenges for
intermediary devices (e.g., traffic monitors, sampling/management
tools) that are inspecting the contents of ESP-NULL packets. For
example, policies on these devices may need to be updated to ensure
that packets that contain the "ROHC" protocol identifier are not
dropped. In addition, intermediary devices may require additional
functionality to determine the content of the header compressed
packets.
In certain scenarios, a ROHCoIPsec implementation may encounter UDP-
encapsulated ESP or IKE packets (i.e., packets that are traversing
NATs). For example, a ROHCoIPsec implementation may receive a UDP-
encapsulated ESP packet that contains an ESP/UDP/IP header chain.
Currently, ROHC profiles do not support compression of the entire
header chain associated with this packet; only the UDP/IP headers can
be compressed.
6. Details of the ROHCoIPsec Framework
6.1. ROHC and IPsec Integration
Figure 2 illustrates the components required to integrate ROHC with
the IPsec process, i.e., ROHCoIPsec.
+-------------------------------+
| ROHC Module |
| |
| |
+-----+ | +-----+ +---------+ |
| | | | | | ROHC | |
--| A |---------| B |-----| Process |------> Path 1
| | | | | | | | (ROHC-enabled SA)
+-----+ | +-----+ +---------+ |
| | | |
| | |-------------------------> Path 2
| | | (ROHC-enabled SA,
| +-------------------------------+ but no compression)
|
|
|
|
+-----------------------------------------> Path 3
(ROHC-disabled SA)
Figure 2. Integration of ROHC with IPsec
The process illustrated in Figure 2 augments the IPsec processing
model for outbound IP traffic (protected-to-unprotected). Initial
IPsec processing is consistent with RFC 4301 [IPSEC] (Section 5.1,
Steps 1-2).
Block A: The ROHC data item (part of the SA state information)
retrieved from the "relevant SAD entry" ([IPSEC], Section 5.1,
Step3a) determines if the traffic traversing the SA is handed to the
ROHC module. Packets selected to a ROHC-disabled SA MUST follow
normal IPsec processing and MUST NOT be sent to the ROHC module
(Figure 2, Path 3). Conversely, packets selected to a ROHC-enabled
SA MUST be sent to the ROHC module.
Block B: This step determines if the packet can be compressed. If
the packet is compressed, an integrity algorithm MAY be used to
compute an Integrity Check Value (ICV) for the uncompressed packet
([IPSEC-ROHC], Section 4.2; [IKE-ROHC], Section 3.1). The Next
Header field of the security protocol header (e.g., ESP, AH) MUST be
populated with a "ROHC" protocol identifier [PROTOCOL], inner packet
headers MUST be compressed, and the computed ICV MAY be appended to
the packet (Figure 2, Path 1). However, if it is determined that the
packet will not be compressed (e.g., due to one of the reasons
described in Section 6.1.3), the Next Header field MUST be populated
with the appropriate value indicating the next-level protocol (Figure
2, Path 2), and ROHC processing MUST NOT be applied to the packet.
After the ROHC process completes, IPsec processing resumes, as
described in Section 5.1, Step3a, of RFC 4301 [IPSEC].
The process illustrated in Figure 2 also augments the IPsec
processing model for inbound IP traffic (unprotected-to-protected).
For inbound packets, IPsec processing is performed ([IPSEC], Section
5.2, Steps 1-3) followed by AH or ESP processing ([IPSEC], Section
5.2, Step 4).
Block A: After AH or ESP processing, the ROHC data item retrieved
from the SAD entry will indicate if traffic traversing the SA is
processed by the ROHC module ([IPSEC], Section 5.2, Step 3a).
Packets traversing a ROHC-disabled SA MUST follow normal IPsec
processing and MUST NOT be sent to the ROHC module. Conversely,
packets traversing a ROHC-enabled SA MUST be sent to the ROHC module.
Block B: The decision at Block B is made using the value of the Next
Header field of the security protocol header. If the Next Header
field does not indicate a ROHC header, the decompressor MUST NOT
attempt decompression (Figure 2, Path 2). If the Next Header field
indicates a ROHC header, decompression is applied. After
decompression, the signaled ROHCoIPsec integrity algorithm MAY be
used to compute an ICV value for the decompressed packet. This ICV,
if present, is compared to the ICV that was calculated at the
compressor. If the ICVs match, the packet is forwarded by the ROHC
module (Figure 2, Path 1); otherwise, the packet MUST be dropped.
Once the ROHC module completes processing, IPsec processing resumes,
as described in Section 5.2, Step 4, of RFC 4301 [IPSEC].
When there is a single SA between a compressor and decompressor, ROHC
MUST operate in unidirectional mode, as described in Section 5 of RFC
3759 [ROHC-TERM]. When there is a pair of SAs instantiated between
ROHCoIPsec implementations, ROHC MAY operate in bi-directional mode,
where an SA pair represents a bi-directional ROHC channel (as
described in Sections 6.1 and 6.2 of RFC 3759 [ROHC-TERM]).
Note that to further reduce the size of an IPsec-protected packet,
ROHCoIPsec and IPComp [IPCOMP] can be implemented in a nested
fashion. This process is detailed in [IPSEC-ROHC], Section 4.4.
6.1.1. Header Compression Protocol Considerations
ROHCv2 [ROHCV2] profiles include various mechanisms that provide
increased robustness over reordering channels. These mechanisms
SHOULD be adopted for ROHC to operate efficiently over IPsec SAs.
A ROHC decompressor implemented within IPsec architecture MAY
leverage additional mechanisms to improve performance over reordering
channels (either due to random events or to an attacker intentionally
reordering packets). Specifically, IPsec's sequence number MAY be
used by the decompressor to identify a packet as "sequentially late".
This knowledge will increase the likelihood of successful
decompression of a reordered packet.
Additionally, ROHCoIPsec implementations SHOULD minimize the amount
of feedback sent from the decompressor to the compressor. If a ROHC
feedback channel is not used sparingly, the overall gains from
ROHCoIPsec can be significantly reduced. More specifically, any
feedback sent from the decompressor to the compressor MUST be
processed by IPsec and tunneled back to the compressor (as designated
by the SA associated with FEEDBACK_FOR). As such, some
implementation alternatives can be considered, including the
following:
o Eliminate feedback traffic altogether by operating only in ROHC
Unidirectional mode (U-mode).
o Piggyback ROHC feedback messages within the feedback element
(i.e., on ROHC traffic that normally traverses the SA designated
by FEEDBACK_FOR).
6.1.2. Initialization and Negotiation of the ROHC Channel
Hop-by-hop ROHC typically uses the underlying link layer (e.g., PPP)
to negotiate ROHC channel parameters. In the case of ROHCoIPsec,
channel parameters can be set manually (i.e., administratively
configured for manual SAs) or negotiated by IKEv2. The extensions
required for IKEv2 to support ROHC channel parameter negotiation are
detailed in [IKE-ROHC].
If the ROHC protocol requires bi-directional communications, two SAs
MUST be instantiated between the IPsec implementations. One of the
two SAs is used for carrying ROHC-traffic from the compressor to the
decompressor, while the other is used to communicate ROHC-feedback
from the decompressor to the compressor. Note that the requirement
for two SAs aligns with the operation of IKE, which creates SAs in
pairs by default. However, IPsec implementations will dictate how
decompressor feedback received on one SA is associated with a
compressor on the other SA. An IPsec implementation MUST relay the
feedback received by the decompressor on an inbound SA to the
compressor associated with the corresponding outbound SA.
6.1.3. Encapsulation and Identification of Header Compressed Packets
As indicated in Section 6.1, new state information (i.e., a new ROHC
data item) is defined for each SA. The ROHC data item MUST be used
by the IPsec process to determine whether it sends all traffic
traversing a given SA to the ROHC module (ROHC-enabled) or bypasses
the ROHC module and sends the traffic through regular IPsec
processing (ROHC-disabled).
The Next Header field of the IPsec security protocol (e.g., AH or
ESP) header MUST be used to demultiplex header-compressed traffic
from uncompressed traffic traversing a ROHC-enabled SA. This
functionality is needed in situations where packets traversing a
ROHC-enabled SA contain uncompressed headers. Such situations may
occur when, for example, a compressor only supports up to n
compressed flows and cannot compress a flow number n+1 that arrives.
Another example is when traffic is selected to a ROHC-enabled SA, but
cannot be compressed by the ROHC process because the appropriate ROHC
Profile has not been signaled for use. As a result, the decompressor
MUST be able to identify packets with uncompressed headers and MUST
NOT attempt to decompress them. The Next Header field is used to
demultiplex these header-compressed and uncompressed packets where
the "ROHC" protocol identifier will indicate that the packet contains
compressed headers. To accomplish this, IANA has allocated value 142
to "ROHC" from the Protocol ID registry [PROTOCOL].
It is noted that the use of the "ROHC" protocol identifier for
purposes other than ROHCoIPsec is currently not defined. In other
words, the "ROHC" protocol identifier is only defined for use in the
Next Header field of security protocol headers (e.g., ESP, AH).
The ROHC Data Item, IANA Protocol ID allocation, and other IPsec
extensions to support ROHCoIPsec are specified in [IPSEC-ROHC].
6.1.4. Motivation for the ROHC ICV
Although ROHC was designed to tolerate packet loss and reordering,
the algorithm does not guarantee that packets reconstructed at the
decompressor are identical to the original packet. As stated in
Section 5.2 of RFC 4224 [REORDR], the consequences of packet
reordering between ROHC peers may include undetected decompression
failures, where erroneous packets are constructed and forwarded to
upper layers. Significant packet loss can have similar consequences.
When using IPsec integrity protection, a packet received at the
egress of an IPsec tunnel is identical to the packet that was
processed at the ingress (given that the key is not compromised,
etc.).
When ROHC is integrated into the IPsec processing framework, the ROHC
processed packet is protected by the AH/ESP ICV. However, bits in
the original IP header are not protected by this ICV; they are
protected only by ROHC's integrity mechanisms (which are designed for
random packet loss/reordering, not malicious packet loss/reordering
introduced by an attacker). Therefore, under certain circumstances,
erroneous packets may be constructed and forwarded into the protected
domain.
To ensure the integrity of the original IP header within the
ROHCoIPsec-processing model, an additional integrity check MAY be
applied before the packet is compressed. This integrity check will
ensure that erroneous packets are not forwarded into the protected
domain. The specifics of this integrity check are documented in
Section 4.2 of [IPSEC-ROHC].
6.1.5. Path MTU Considerations
By encapsulating IP packets with AH/ESP and tunneling IP headers,
IPsec increases the size of IP packets. This increase may result in
Path MTU issues in the unprotected domain. Several approaches to
resolving these path MTU issues are documented in Section 8 of RFC
4301 [IPSEC]; approaches include fragmenting the packet before or
after IPsec processing (if the packet's Don't Fragment (DF) bit is
clear), or possibly discarding packets (if the packet's DF bit is
set).
The addition of ROHC within the IPsec processing model may result in
similar path MTU challenges. For example, under certain
circumstances, ROHC headers are larger than the original uncompressed
headers. In addition, if an integrity algorithm is used to validate
packet headers, the resulting ICV will increase the size of packets.
Both of these properties of ROHCoIPsec increase the size of packets,
and therefore may result in additional challenges associated with
path MTU.
Approaches to addressing these path MTU issues are specified in
Section 4.3 of [IPSEC-ROHC].
6.2. ROHCoIPsec Framework Summary
To summarize, the following items are needed to achieve ROHCoIPsec:
o IKEv2 Extensions to Support ROHCoIPsec
o IPsec Extensions to Support ROHCoIPsec
7. Security Considerations
Several security considerations associated with the use of ROHCoIPsec
are covered in Section 6.1.4. These considerations can be mitigated
by using a strong integrity-check algorithm to ensure the valid
decompression of packet headers.
A malfunctioning or malicious ROHCoIPsec compressor (i.e., the
compressor located at the ingress of the IPsec tunnel) has the
ability to send erroneous packets to the decompressor (i.e., the
decompressor located at the egress of the IPsec tunnel) that do not
match the original packets emitted from the end-hosts. Such a
scenario may result in decreased efficiency between compressor and
decompressor, or may cause the decompressor to forward erroneous
packets into the protected domain. A malicious compressor could also
intentionally generate a significant number of compressed packets,
which may result in denial of service at the decompressor, as the
decompression of a significant number of invalid packets may drain
the resources of an IPsec device.
A malfunctioning or malicious ROHCoIPsec decompressor has the ability
to disrupt communications as well. For example, a decompressor may
simply discard a subset of (or all) the packets that are received,
even if packet headers were validly decompressed. Ultimately, this
could result in denial of service. A malicious decompressor could
also intentionally indicate that its context is not synchronized with
the compressor's context, forcing the compressor to transition to a
lower compression state. This will reduce the overall efficiency
gain offered by ROHCoIPsec.
8. IANA Considerations
All IANA considerations for ROHCoIPsec are documented in [IKE-ROHC]
and [IPSEC-ROHC].
9. Acknowledgments
The authors would like to thank Sean O'Keeffe, James Kohler, and
Linda Noone of the Department of Defense, as well as Rich Espy of
OPnet for their contributions and support in the development of this
document.
The authors would also like to thank Yoav Nir and Robert A Stangarone
Jr.: both served as committed document reviewers for this
specification.
In addition, the authors would like to thank the following for their
numerous reviews and comments to this document:
o Magnus Westerlund
o Stephen Kent
o Pasi Eronen
o Joseph Touch
o Tero Kivinen
o Jonah Pezeshki
o Lars-Erik Jonsson
o Jan Vilhuber
o Dan Wing
o Kristopher Sandlund
o Ghyslain Pelletier
o David Black
o Tim Polk
o Brian Carpenter
Finally, the authors would also like to thank Tom Conkle, Renee
Esposito, Etzel Brower, and Michele Casey of Booz Allen Hamilton for
their assistance in completing this work.
10. Informative References
[ROHC] Sandlund, K., Pelletier, G., and L-E. Jonsson, "The
RObust Header Compression (ROHC) Framework", RFC 5795,
March 2010.
[IPSEC] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, December 2005.
[ROHC-TERM] Jonsson, L-E., "Robust Header Compression (ROHC):
Terminology and Channel Mapping Examples", RFC 3759,
April 2004.
[BRA97] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[IKEV2] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol",
RFC 4306, December 2005.
[ESP] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, December 2005.
[AH] Kent, S., "IP Authentication Header", RFC 4302,
December 2005.
[IPSEC-ROHC] Ertekin, E., Christou, C., and C. Bormann, "IPsec
Extensions to Support Robust Header Compression over
IPsec", RFC 5858, May 2010.
[IKE-ROHC] Ertekin, E., Christou, C., Jasani, R., Kivinen, T., and
C. Bormann, "IKEv2 Extensions to Support Robust Header
Compression over IPsec", RFC 5857, May 2010.
[PROTOCOL] IANA, "Assigned Internet Protocol Numbers",
<http://www.iana.org>.
[IPCOMP] Shacham, A., Monsour, B., Pereira, R., and M. Thomas,
"IP Payload Compression Protocol (IPComp)", RFC 3173,
September 2001.
[ROHCV2] Pelletier, G. and K. Sandlund, "RObust Header
Compression Version 2 (ROHCv2): Profiles for RTP, UDP,
IP, ESP and UDP-Lite", RFC 5225, April 2008.
[REORDR] Pelletier, G., Jonsson, L-E., and K. Sandlund, "RObust
Header Compression (ROHC): ROHC over Channels That Can
Reorder Packets", RFC 4224, January 2006.
Authors' Addresses
Emre Ertekin
Booz Allen Hamilton
5220 Pacific Concourse Drive, Suite 200
Los Angeles, CA 90045
US
EMail: ertekin_emre@bah.com
Rohan Jasani
Booz Allen Hamilton
13200 Woodland Park Dr.
Herndon, VA 20171
US
EMail: ro@breakcheck.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