draft-ietf-sigtran-security-00.txt   draft-ietf-sigtran-security-01.txt 
Network Working Group J. Loughney Network Working Group J. Loughney
Internet-Draft Nokia Research Center Internet-Draft Nokia Research Center
Expires: April 28, 2003 M. Tuexen Expires: August 1, 2003 M. Tuexen
Siemens AG Siemens AG
J. Pastor-Balbas J. Pastor-Balbas
Ericsson Ericsson
October 28, 2002 January 31, 2003
Security Considerations for SIGTRAN Protocols Security Considerations for SIGTRAN Protocols
draft-ietf-sigtran-security-00.txt draft-ietf-sigtran-security-01.txt
Status of this Memo Status of this Memo
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Copyright Notice Copyright Notice
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Abstract Abstract
This documents discusses how TLS and IPSec can be used to secure the This documents discusses how TLS and IPSec can be used to secure the
communication which is based on SIGTRAN protocols. communication for SIGTRAN protocols. The support of IPSec is
mandatory for all nodes running SIGTRAN protocols and the support of
Table of Contents TLS is optional.
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Security in telephony networks . . . . . . . . . . . . . . . . 5
3. Threats . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Protecting Confidentiality . . . . . . . . . . . . . . . . . . 7
5. IPSec Usage . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. TLS Usage . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Peer-to-Peer Considerations . . . . . . . . . . . . . . . . . 11
8. Security Considerations . . . . . . . . . . . . . . . . . . . 13
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15
References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 17
Full Copyright Statement . . . . . . . . . . . . . . . . . . . 18
1. Introduction 1. Introduction
1.1 Overview 1.1 Overview
The SIGTRAN protocols are designed to carry signaling messages for The SIGTRAN protocols are designed to carry signaling messages for
telephony services. These protocols will be used between telephony services. These protocols will be used between
o customer premise and service provider equipment in case of IUA o customer premise and service provider equipment in case of IUA
skipping to change at page 3, line 29 skipping to change at page 2, line 27
SIGTRAN protocols involve the security needs of several parties: the SIGTRAN protocols involve the security needs of several parties: the
end-users of the services; the service providers and the applications end-users of the services; the service providers and the applications
involved. Additional security requirements may come from local involved. Additional security requirements may come from local
regulation. While having some overlapping security needs, any regulation. While having some overlapping security needs, any
security solution should fulfill all of the different parties' needs. security solution should fulfill all of the different parties' needs.
The SIGTRAN protocols assume that messages are secured by using The SIGTRAN protocols assume that messages are secured by using
either IPSec or TLS. either IPSec or TLS.
1.2 Terminology 1.2 Abbreviations
This document uses the following terms:
TBD: TDB.
1.3 Abbreviations
This document uses the following abbreviations: This document uses the following abbreviations:
CA: Certificate Authority. CA: Certificate Authority.
DOI: Domain Of Interpretation. DOI: Domain Of Interpretation.
ESP: Encapsulating Security Payload. ESP: Encapsulating Security Payload.
FQDN: Full-Qualified Domain Names. FQDN: Full-Qualified Domain Names.
IPSec: IP Security Protocol. IPSec: IP Security Protocol.
IKE: Internet Key Exchange Protocol. IKE: Internet Key Exchange Protocol.
ISDN: Integrated Services Digital Network.
IUA: ISDN Q.921 User Adaptation Layer. IUA: ISDN Q.921 User Adaptation Layer.
M2PA: SS7 MTP2 Peer-to-Peer User Adaptation Layer. M2PA: SS7 MTP2 Peer-to-Peer User Adaptation Layer.
M2UA: SS7 MTP2 User Adaptation Layer. M2UA: SS7 MTP2 User Adaptation Layer.
M3UA: SS7 MTP3 User Adaptation Layer. M3UA: SS7 MTP3 User Adaptation Layer.
PKI: Public Key Infrastructure.
SA: Security Association. SA: Security Association.
SCTP: Stream Control Transmission Protocol. SCTP: Stream Control Transmission Protocol.
SS7: Signaling System No. 7. SS7: Signaling System No. 7.
SUA: SS7 SCCP User Adaptation Layer. SUA: SS7 SCCP User Adaptation Layer.
TLS: Transport Layer Security. TLS: Transport Layer Security.
2. Security in telephony networks 2. Convention
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when
they appear in this document, are to be interpreted as described in
[1].
3. Security in telephony networks
The security in telephony networks is mainly based on the trusted The security in telephony networks is mainly based on the trusted
network principle. There are two totally different protocol used: network principle. There are two main protocols used: Access
The ISDN access protocol is used for signaling in the access network protocols (ISDN and others) are used for signaling in the access
and the SS7 protocol stack in the core network. network and the SS7 protocol stack in the core network.
As SS7 networks are often physically remoter and/or inacessable, it As SS7 networks are often physically remote and/or inaccessible to
is assumed that they are protected from malicious users. Often, the user, it is assumed that they are protected from malicious users.
equipment is under lock and key. At network boundaries between SS7 Often, equipment is under lock and key. At network boundaries
networks, packet filtering is sometimes used. End-users are not between SS7 networks, packet filtering is sometimes used. End-users
directly connected to SS7 networks. are not directly connected to SS7 networks.
The ISDN access protocol is the separate protocol stack for end-user The access protocols are used for end-user signaling. End-user
signaling. End-user signaling protocols are translated to SS7 based signaling protocols are translated to SS7 based protocols by
protocols by telephone switches run by network operators. telephone switches run by network operators.
Often Regulatory Authorities require SS7 switches with connections to Often Regulatory Authorities require SS7 switches with connections to
different SS7 to be conformant to national and/or international test different SS7 to be conformant to national and/or international test
specifications. specifications.
There are no standardized ways of using encryption technologies for There are no standardized ways of using encryption technologies for
providing confidentiality or using technologies for authentication. providing confidentiality or using technologies for authentication.
This description applies to telephony networks operated by a single This description applies to telephony networks operated by a single
operator but also to multiple telephony networks being connected and operator but also to multiple telephony networks being connected and
operated by different operators. operated by different operators.
3. Threats 4. Threats and Goals
There is no quick fix, one-size-fits-all solution for security. All The Internet threats can be divided into one of two main types. The
SIGTRAN protocols have the following security objectives: first one is called "passive attacks". It happens whenever the
attacker reads packets off the network but does not write them.
Examples of such attacks include confidentiality violations, password
sniffing and offline cryptographic attacks amongst others.
o Availability of reliable and timely user data transport. The second kind of threads is called "active attacks". In this case
the attacker also writes data to the network. Examples for this
attack include replay attacks, message insertion, message deletion,
message modification or man in the middle attacks amongst others.
o Authentication of peers. In general, Internet protocols have the following security
objectives:
o Integrity of user data transport. o Communication Security:
o Confidentiality of user data. * Authentication of peers.
* Integrity of user data transport.
* Confidentiality of user data.
o Non-repudation.
o System Security, avoidance of:
* Unauthorized use.
* Unappropiate use.
* Denial of Service.
Communication security is mandatory in some network scenarios to
prevent malicious attacks. The main goal of this document is to
recommend the minimum security means that a SIGTRAN node must
implement in order to achieve a secured communication. To get this
goal, we will explore the different security options that regarding
communication exist.
All SIGTRAN protocols use the Stream Control Transmission Protocol All SIGTRAN protocols use the Stream Control Transmission Protocol
(SCTP) being defined in [7] and [9] as its transport protocol. SCTP (SCTP) being defined in [8] and [10] as its transport protocol. SCTP
provides certain transport related security features, such as: provides certain transport related security features, such as
resistance against:
o Blind Denial of Service Attacks o Blind Denial of Service Attacks such as:
o Flooding * Flooding
o Masquerade * Masquerade
o Improper Monopolization of Services * Improper Monopolization of Services
When SIGTRAN protocols are running in professionally managed There is no quick fix, one-size-fits-all solution for security.
corporate or service provider network, it is reasonable to expect
that this network include an appropriate security policy framework.
The "Site Security Handbook" [1] should be consulted for guidance.
When the network in which SIGTRAN protocols are used involves more When the network in which SIGTRAN protocols are used involves more
than one party, it may not be reasonable to expect that all parties than one party, it may not be reasonable to expect that all parties
have implemented security in a sufficient manner. End-to-end have implemented security in a sufficient manner. End-to-end
security should be the goal; therefore, it is recommended that IPSec security should be the goal; therefore, it is recommended that IPSec
or TLS is used to ensure confidentiality of user payload. Consult or TLS is used to ensure confidentiality of user payload. Consult
[3] for more information on configuring IPSec services. [4] for more information on configuring IPSec services.
4. Protecting Confidentiality
If SIGTRAN information has to be protected either IPSec ESP in
transport mode or TLS can be used. In both cases the IP header
information is neither encrypted nor protected. If IPSec ESP is
chosen the SCTP control information is encrypted and protected
whereas if the TLS based solution the SCTP control information is not
encrypted and only protected by SCTP procedures.
5. IPSec Usage 5. IPSec Usage
This section is relevant only for SIGTRAN nodes using IPSec to secure This section is relevant only for SIGTRAN nodes using IPSec to secure
communication between SIGTRAN node. communication between SIGTRAN nodes.
All SIGTRAN nodes using IPSec MUST support IPsec ESP [4] in transport All SIGTRAN nodes using IPSec MUST support IPSec ESP [5] in transport
mode with non-null encryption and authentication algorithms to mode with non-null encryption and authentication algorithms to
provide per-packet authentication, integrity protection and provide per-packet authentication, integrity protection and
confidentiality, and MUST support the replay protection mechanisms of confidentiality, and MUST support the replay protection mechanisms of
IPSec. IPSec. In those scenarios where IP layer protection is needed, ESP
in tunnel mode SHOULD be used.
These nodes MUST support IKE for peer authentication, negotiation of These nodes MUST support IKE for peer authentication, negotiation of
security associations, and key management, using the IPsec DOI [5]. security associations, and key management, using the IPSec DOI [6].
The IPSec implementations MUST support peer authentication using a The IPSec implementations MUST support peer authentication using a
pre-shared key, and MAY support certificate-based peer authentication pre-shared key, and MAY support certificate-based peer authentication
using digital signatures. Peer authentication using the public key using digital signatures. Peer authentication using the public key
encryption methods outlined in IKE's sections 5.2 and 5.3 [6] SHOULD encryption methods outlined in IKE's sections 5.2 and 5.3 [7] SHOULD
NOT be used. NOT be used.
Conformant implementations MUST support both IKE Main Mode and Conformant implementations MUST support both IKE Main Mode and
Aggressive Mode. When pre-shared keys are used for authentication, Aggressive Mode. For transport mode, when pre-shared keys are used
IKE Aggressive Mode SHOULD be used, and IKE Main Mode SHOULD NOT be for authentication, IKE Aggressive Mode SHOULD be used, and IKE Main
used. When digital signatures are used for authentication, either Mode SHOULD NOT be used. When digital signatures are used for
IKE Main Mode or IKE Aggressive Mode MAY be used. authentication, either IKE Main Mode or IKE Aggressive Mode MAY be
used. When using ESP tunnel mode, IKE Main Mode MAY be used to
create ISAKMP association with identity protection during Phase 1.
When digital signatures are used to achieve authentication, an IKE When digital signatures are used to achieve authentication, an IKE
negotiator SHOULD use IKE Certificate Request Payload(s) to specify negotiator SHOULD use IKE Certificate Request Payload(s) to specify
the certificate authority (or authorities) that are trusted in the certificate authority (or authorities) that are trusted in
accordance with its local policy. IKE negotiators SHOULD use accordance with its local policy. IKE negotiators SHOULD use
pertinent certificate revocation checks before accepting a PKI pertinent certificate revocation checks before accepting a PKI
certificate for use in IKE's authentication procedures. certificate for use in IKE's authentication procedures.
The Phase 2 Quick Mode exchanges used to negotiate protection for The Phase 2 Quick Mode exchanges used to negotiate protection for
SIGTRAN sessions MUST explicitly carry the Identity Payload fields SIGTRAN sessions MUST explicitly carry the Identity Payload fields
(IDci and IDcr). The DOI provides for several types of (IDci and IDcr). The DOI provides for several types of
identification data. However, when used in conformant identification data. However, when used in conformant
implementations, each ID Payload MUST carry a single IP address and a implementations, each ID Payload MUST carry a single IP address and a
single non-zero port number, and MUST NOT use the IP Subnet or IP single non-zero port number, and MUST NOT use the IP Subnet or IP
Address Range formats. This allows the Phase 2 security association Address Range formats. This allows the Phase 2 security association
to correspond to specific TCP and SCTP connections. to correspond to specific TCP and SCTP connections.
Since IPsec acceleration hardware may only be able to handle a Since IPSec acceleration hardware may only be able to handle a
limited number of active IKE Phase 2 SAs, Phase 2 delete messages may limited number of active IKE Phase 2 SAs, Phase 2 delete messages may
be sent for idle SAs, as a means of keeping the number of active be sent for idle SAs, as a means of keeping the number of active
Phase 2 SAs to a minimum. The receipt of an IKE Phase 2 delete Phase 2 SAs to a minimum. The receipt of an IKE Phase 2 delete
message SHOULD NOT be interpreted as a reason for tearing down a message SHOULD NOT be interpreted as a reason for tearing down a
SIGTRAN session. Rather, it is preferable to leave the connection SIGTRAN session. Rather, it is preferable to leave the connection
up, and if additional traffic is sent on it, to bring up another IKE up, and if additional traffic is sent on it, to bring up another IKE
Phase 2 SA to protect it. This avoids the potential for continually Phase 2 SA to protect it. This avoids the potential for continually
bringing connections up and down. bringing connections up and down.
It should be noted that SCTP supports multi-homed hosts and this It should be noted that SCTP supports multi-homed hosts and this
results in the need for having multiple security associations for one results in the need for having multiple security associations for one
SCTP association. This disadvantage of IPSec has been addressed by SCTP association. This disadvantage of IPSec has been addressed by
[14]. So IPSec implementations used by SIGTRAN nodes SHOULD support [15]. So IPSec implementations used by SIGTRAN nodes SHOULD support
the IPSec feature described in [14]. the IPSec feature described in [15].
6. TLS Usage 6. TLS Usage
This section is relevant only for SIGTRAN nodes using TLS to secure This section is relevant only for SIGTRAN nodes using TLS to secure
the communication between SIGTRAN nodes. the communication between SIGTRAN nodes.
A SIGTRAN node that initiates a SCTP association to another SIGTRAN A SIGTRAN node that initiates a SCTP association to another SIGTRAN
node acts as a TLS client according to [2], and a SIGTRAN node that node acts as a TLS client according to [3], and a SIGTRAN node that
accepts a connection acts as a TLS server. SIGTRAN peers accepts a connection acts as a TLS server. SIGTRAN peers
implementing TLS for security MUST mutually authenticate as part of implementing TLS for security MUST mutually authenticate as part of
TLS session establishment. In order to ensure mutual authentication, TLS session establishment. In order to ensure mutual authentication,
the SIGTRAN node acting as TLS server must request a certificate from the SIGTRAN node acting as TLS server must request a certificate from
the SIGTRAN node acting as TLS client, and the SIGTRAN node acting as the SIGTRAN node acting as TLS client, and the SIGTRAN node acting as
TLS client MUST be prepared to supply a certificate on request. TLS client MUST be prepared to supply a certificate on request.
[13] requires the support of the cipher suite [13] requires the support of the cipher suite
TLS_RSA_WITH_AES_128_CBC_SHA. SIGTRAN nodes MAY negotiate other TLS TLS_RSA_WITH_AES_128_CBC_SHA. SIGTRAN nodes MAY negotiate other TLS
cipher suites. cipher suites.
TLS MUST be used on all bi-directional streams and the other uni- TLS MUST be used on all bi-directional streams and the other
directional streams MUST NOT be used. uni-directional streams MUST NOT be used.
It should also be noted that a SCTP implementation used for TLS over It should also be noted that a SCTP implementation used for TLS over
SCTP MUST support fragmentation of user data and might also need to SCTP MUST support fragmentation of user data and might also need to
support the partial delivery API. This holds even if all SIGTRAN support the partial delivery API. This holds even if all SIGTRAN
messages are small. See [13] for more details. messages are small. See [13] for more details.
The SIGTRAN protocols use separate SCTP port numbers and payload The SIGTRAN protocols use the same SCTP port number and payload
protocol identifiers when run over TLS. These numbers are given in protocol identifier when run over TLS. A session upgrade procedure
Section 9. A SIGTRAN session MUST be aborted if the port number or has to used to initiate the TLS based communication.
payload protocol identifier indicates the use of TLS and it is not
used.
As an alternative to a separate port number, a session upgrade Because TLS only protects the payload the SCTP header and all control
procedure can be used. This needs an extension for all adaptation chunks are not protected. This can be used for DoS attacks. This is
layers allowing the SIGTRAN protocols to use the same port number in a general problem with security provided at the transport layer.
the case where TLS is used or not. This needs further discussions.
7. Peer-to-Peer Considerations 7. Support of IPSec and TLS
If content of SIGTRAN protocol messages is to be protected, either
IPSec ESP in transport mode or TLS can be used. In both cases the IP
header information is neither encrypted nor protected. If IPSec ESP
is chosen the SCTP control information is encrypted and protected
whereas if the TLS based solution the SCTP control information is not
encrypted and only protected by SCTP procedures.
In general, both IPSec and TLS have enough mechanisms to secure the
SIGTRAN communications. Nevertheless, due to the wider deployment of
IPSec, it is foreseen a faster development and market support for
this protocol.
Therefore, in order to have a secured model working as soon as
possible, the following recommendation is made: A SIGTRAN node MUST
support IPSec and MAY support TLS.
8. Peer-to-Peer Considerations
M2PA, M3UA and SUA support the peer-to-peer model as a generalization M2PA, M3UA and SUA support the peer-to-peer model as a generalization
to the client-server model which is supported by IUA and M2UA. A to the client-server model which is supported by IUA and M2UA. A
SIGTRAN node running M2PA, M3UA or SUA and operating in the peer-to- SIGTRAN node running M2PA, M3UA or SUA and operating in the
peer mode is called a SIGTRAN peer. peer-to-peer mode is called a SIGTRAN peer.
As with any peer-to-peer protocol, proper configuration of the trust As with any peer-to-peer protocol, proper configuration of the trust
model within a peer is essential to security. When certificates are model within a peer is essential to security. When certificates are
used, it is necessary to configure the root certificate authorities used, it is necessary to configure the root certificate authorities
trusted by the peer. These root CAs are likely to be unique to trusted by the peer. These root CAs are likely to be unique to
SIGTRAN usage and distinct from the root CAs that might be trusted SIGTRAN usage and distinct from the root CAs that might be trusted
for other purposes such as Web browsing. In general, it is expected for other purposes such as Web browsing. In general, it is expected
that those root CAs will be configured so as to reflect the business that those root CAs will be configured so as to reflect the business
relationships between the organization hosting the peer and other relationships between the organization hosting the peer and other
organizations. As a result, a peer will typically not be configured organizations. As a result, a peer will typically not be configured
to allow connectivity with any arbitrary peer. When certificate to allow connectivity with any arbitrary peer. When certificate
authentication peers may not be known beforehand, and therefore peer authentication peers may not be known beforehand, and therefore peer
discovery may be required. discovery may be required.
Note that IPsec is considerably less flexible than TLS when it comes Note that IPSec is considerably less flexible than TLS when it comes
to configuring root CAs. Since use of Port identifiers is prohibited to configuring root CAs. Since use of Port identifiers is prohibited
within IKE Phase 1, within IPsec it is not possible to uniquely within IKE Phase 1, within IPSec it is not possible to uniquely
configure trusted root CAs for each application individually; the configure trusted root CAs for each application individually; the
same policy must be used for all applications. This implies, for same policy must be used for all applications. This implies, for
example, that a root CA trusted for use with a SIGTRAN protocol must example, that a root CA trusted for use with a SIGTRAN protocol must
also be trusted to protect SNMP. These restrictions can be awkward also be trusted to protect SNMP. These restrictions can be awkward
at best. Since TLS supports application-level granularity in at best. Since TLS supports application-level granularity in
certificate policy, TLS SHOULD be used to protect SIGTRAN sessions certificate policy, TLS SHOULD be used to protect SIGTRAN sessions
between administrative domains. IPsec is most appropriate for intra- between administrative domains. IPSec is most appropriate for
domain usage when pre-shared keys are used as a security mechanism. intra-domain usage when pre-shared keys are used as a security
mechanism.
When pre-shared key authentication is used with IPSec to protect When pre-shared key authentication is used with IPSec to protect
SIGTRAN based communication, unique pre-shared keys are configured SIGTRAN based communication, unique pre-shared keys are configured
with peers, who are identified by their IP address (Main Mode), or with peers, who are identified by their IP address (Main Mode), or
possibly their FQDN (AggressivenMode). As a result, it is necessary possibly their FQDN (AggressivenMode). As a result, it is necessary
for the set of peers to be known beforehand. Therefore, peer for the set of peers to be known beforehand. Therefore, peer
discovery is typically not necessary. discovery is typically not necessary.
The following is intended to provide some guidance on the issue. The following is intended to provide some guidance on the issue.
It is recommended that SIGTRAN peers use the same security mechanism It is recommended that SIGTRAN peers use the same security mechanism
(IPSec or TLS) across all its sessions with other SIGTRAN peers. (IPSec or TLS) across all its sessions with other SIGTRAN peers.
Inconsistent use of security mechanisms can result in redundant Inconsistent use of security mechanisms can result in redundant
security mechanisms being used (e.g. TLS over IPsec) or worse, security mechanisms being used (e.g. TLS over IPSec) or worse,
potential security vulnerabilities. When IPsec is used with a potential security vulnerabilities. When IPSec is used with a
SIGTRAN protocol, a typical security policy for outbound traffic is SIGTRAN protocol, a typical security policy for outbound traffic is
"Initiate IPsec, from me to any, destination port P"; for inbound "Initiate IPSec, from me to any, destination port P"; for inbound
traffic, the policy would be "Require IPsec, from any to me, traffic, the policy would be "Require IPSec, from any to me,
destination port P". Here P denotes one of the registered port destination port P". Here P denotes one of the registered port
numbers for a SIGTRAN protocol. numbers for a SIGTRAN protocol.
This policy causes IPSec to be used whenever a SIGTRAN peer initiates This policy causes IPSec to be used whenever a SIGTRAN peer initiates
a session to another SIGTRAN peer, and to be required whenever an a session to another SIGTRAN peer, and to be required whenever an
inbound SIGTRAN session occurs. This policy is attractive, since it inbound SIGTRAN session occurs. This policy is attractive, since it
does not require policy to be set for each peer or dynamically does not require policy to be set for each peer or dynamically
modified each time a new SIGTRAN session is created; an IPSec SA is modified each time a new SIGTRAN session is created; an IPSec SA is
automatically created based on a simple static policy. Since IPSec automatically created based on a simple static policy. Since IPSec
extensions are typically not available to the sockets API on most extensions are typically not available to the sockets API on most
platforms, and IPsec policy functionality is implementation platforms, and IPSec policy functionality is implementation
dependent, use of a simple static policy is the often the simplest dependent, use of a simple static policy is the often the simplest
route to IPSec-enabling a SIGTRAN peer. route to IPSec-enabling a SIGTRAN peer.
If IPSec is used to secure SIGTRAN peer-to-peer session, IPSec policy If IPSec is used to secure SIGTRAN peer-to-peer session, IPSec policy
SHOULD be set so as to require IPsec protection for inbound SHOULD be set so as to require IPSec protection for inbound
connections, and to initiate IPsec protection for outbound connections, and to initiate IPSec protection for outbound
connections. This can be accomplished via use of inbound and connections. This can be accomplished via use of inbound and
outbound filter policy. outbound filter policy.
8. Security Considerations 9. Security Considerations
This documents discusses the usage of IPSec and TLS for securing This documents discusses the usage of IPSec and TLS for securing
SIGTRAN traffic. SIGTRAN traffic.
9. IANA Considerations 10. IANA Considerations
SCTP port numbers and SCTP payload protocol identifiers have to be
registered for:
o IUA over TLS
o M2UA over TLS
o M2PA over TLS No actions have to be taken by IANA.
o M3UA over TLS 11. Acknowledgements
o SUA over TLS The authors would like to thank B. Aboba, K. Morneault and many
others for their invaluable comments and suggestions.
10. Acknowledgements Normative References
The authors would like to thank K. Morneau and many others for their [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
invaluable comments and suggestions. Levels", BCP 14, RFC 2119, March 1997.
References [2] Bradner, S., "The Internet Standards Process -- Revision 3", BCP
9, RFC 2026, October 1996.
[1] Fraser, B., "Site Security Handbook", RFC 2196, September 1997. Informative References
[2] Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A. and [3] Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A. and
P. Kocher, "The TLS Protocol Version 1.0", RFC 2246, January P. Kocher, "The TLS Protocol Version 1.0", RFC 2246, January
1999. 1999.
[3] Kent, S. and R. Atkinson, "Security Architecture for the [4] Kent, S. and R. Atkinson, "Security Architecture for the
Internet Protocol", RFC 2401, November 1998. Internet Protocol", RFC 2401, November 1998.
[4] Kent, S. and R. Atkinson, "IP Encapsulating Security Payload [5] Kent, S. and R. Atkinson, "IP Encapsulating Security Payload
(ESP)", RFC 2406, November 1998. (ESP)", RFC 2406, November 1998.
[5] Piper, D., "The Internet IP Security Domain of Interpretation [6] Piper, D., "The Internet IP Security Domain of Interpretation
for ISAKMP", RFC 2407, November 1998. for ISAKMP", RFC 2407, November 1998.
[6] Harkins, D. and D. Carrel, "The Internet Key Exchange (IKE)", [7] Harkins, D. and D. Carrel, "The Internet Key Exchange (IKE)",
RFC 2409, November 1998. RFC 2409, November 1998.
[7] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer, [8] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer,
H., Taylor, T., Rytina, I., Kalla, M., Zhang, L. and V. Paxson, H., Taylor, T., Rytina, I., Kalla, M., Zhang, L. and V. Paxson,
"Stream Control Transmission Protocol", RFC 2960, October 2000. "Stream Control Transmission Protocol", RFC 2960, October 2000.
[8] Morneault, K., Rengasami, S., Kalla, M. and G. Sidebottom, [9] Morneault, K., Rengasami, S., Kalla, M. and G. Sidebottom,
"ISDN Q.921-User Adaptation Layer", RFC 3057, February 2001. "ISDN Q.921-User Adaptation Layer", RFC 3057, February 2001.
[9] Stone, J., Stewart, R. and D. Otis, "Stream Control [10] Stone, J., Stewart, R. and D. Otis, "Stream Control
Transmission Protocol (SCTP) Checksum Change", RFC 3309, Transmission Protocol (SCTP) Checksum Change", RFC 3309,
September 2002. September 2002.
[10] Morneault, K., Dantu, R., Sidebottom, G., Bidulock, B. and J. [11] Morneault, K., Dantu, R., Sidebottom, G., Bidulock, B. and J.
Heitz, "Signaling System 7 (SS7) Message Transfer Part 2 (MTP2) Heitz, "Signaling System 7 (SS7) Message Transfer Part 2 (MTP2)
- User Adaptation Layer", RFC 3331, September 2002. - User Adaptation Layer", RFC 3331, September 2002.
[11] Sidebottom, G., Morneault, K. and J. Pastor-Balbas, "Signaling [12] Sidebottom, G., Morneault, K. and J. Pastor-Balbas, "Signaling
System 7 (SS7) Message Transfer Part 3 (MTP3) - User Adaptation System 7 (SS7) Message Transfer Part 3 (MTP3) - User Adaptation
Layer (M3UA)", RFC 3332, September 2002. Layer (M3UA)", RFC 3332, September 2002.
[12] George, T., "SS7 MTP2-User Peer-to-Peer Adaptation Layer", [13] Tuexen, M., Jungmaier, A. and E. Rescorla, "Transport Layer
draft-ietf-sigtran-m2pa-06 (work in progress), August 2002. Security over Stream Control Transmission Protocol", RFC 3436,
December 2002.
[13] Rescorla, E., Tuexen, M. and A. Jungmaier, "TLS over SCTP", [14] George, T., "SS7 MTP2-User Peer-to-Peer Adaptation Layer",
draft-ietf-tsvwg-tls-over-sctp-00 (work in progress), November draft-ietf-sigtran-m2pa-07 (work in progress), January 2003.
2001.
[14] Bellovin, S., "On the Use of SCTP with IPsec", draft-ietf- [15] Bellovin, S., "On the Use of SCTP with IPsec",
ipsec-sctp-04 (work in progress), October 2002. draft-ietf-ipsec-sctp-04 (work in progress), October 2002.
Authors' Addresses Authors' Addresses
John Loughney John Loughney
Nokia Research Center Nokia Research Center
PO Box 407 PO Box 407
FIN-00045 Nokia Group FIN-00045 Nokia Group
Finland Finland
EMail: john.loughney@nokia.com EMail: john.loughney@nokia.com
skipping to change at page 17, line 22 skipping to change at page 11, line 4
EMail: john.loughney@nokia.com EMail: john.loughney@nokia.com
Michael Tuexen Michael Tuexen
Siemens AG Siemens AG
Hofmannstr. 51 Hofmannstr. 51
81359 Munich 81359 Munich
Germany Germany
EMail: Michael.Tuexen@siemens.com EMail: Michael.Tuexen@siemens.com
Javier Pastor-Balbas Javier Pastor-Balbas
Ericsson Ericsson
? Avenida de los Poblados, 13
Madrid 28033 Madrid
Spain Spain
EMail: javier.pastor-balbas@ece.ericsson.se EMail: javier.pastor-balbas@ece.ericsson.se
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 End of changes. 

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