HIP Working Group A. Keranen
Internet-Draft J. Melen
Intended status: Experimental Ericsson
Expires: October 11, 2010 April 9, 2010
Native NAT Traversal Mode for the Host Identity Protocol
draft-keranen-hip-native-nat-traversal-01
Abstract
This document specifies a new Network Address Translator (NAT)
traversal mode for the Host Identity Protocol (HIP). The new mode is
based on the Interactive Connectivity Establishment (ICE) methodology
and UDP encapsulation of data and signaling traffic. The main
difference from the previously specified modes is the use of HIP
messages for all NAT traversal procedures.
Status of this Memo
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This Internet-Draft will expire on October 11, 2010.
Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Protocol Description . . . . . . . . . . . . . . . . . . . . . 4
3.1. Relay Registration . . . . . . . . . . . . . . . . . . . . 4
3.2. Registration Authentication . . . . . . . . . . . . . . . 4
3.3. Forwarding Rules and Permissions . . . . . . . . . . . . . 5
3.4. Relaying UDP Encapsulated Data and Control Packets . . . . 6
3.5. Candidate Gathering . . . . . . . . . . . . . . . . . . . 7
3.6. Base Exchange via HIP Relay Server . . . . . . . . . . . . 7
3.7. Native NAT Traversal Mode Negotiation . . . . . . . . . . 7
3.8. Connectivity Check Pacing Negotiation . . . . . . . . . . 7
3.9. Connectivity Checks . . . . . . . . . . . . . . . . . . . 8
3.10. NAT Keepalives . . . . . . . . . . . . . . . . . . . . . . 8
3.11. Handling Conflicting SPI Values . . . . . . . . . . . . . 9
4. Packet Formats . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1. RELAYED_ADDRESS and MAPPED_ADDRESS Parameters . . . . . . 9
4.2. PEER_PERMISSION Parameter . . . . . . . . . . . . . . . . 10
4.3. HIP Connectivity Check Packets . . . . . . . . . . . . . . 11
5. Security Considerations . . . . . . . . . . . . . . . . . . . 12
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
8.1. Normative References . . . . . . . . . . . . . . . . . . . 13
8.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14
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1. Introduction
The Host Identity Protocol (HIP) [RFC5201] is specified to run
directly on top of IPv4 or IPv6. However, many middleboxes found in
the Internet, such as NATs and firewalls, often allow only UDP or TCP
traffic to pass [RFC5207]. Also, especially NATs usually require the
host behind a NAT to create a forwarding state in the NAT before
other hosts outside of the NAT can contact the host behind the NAT.
To overcome this problem, different methods, commonly referred to as
NAT traversal techniques, have been developed.
Two NAT traversal techniques for HIP are specified in
[I-D.ietf-hip-nat-traversal]. One of them uses only UDP
encapsulation, while the other uses also the Interactive Connectivity
Establishment (ICE) [I-D.ietf-mmusic-ice] protocol, which in turn
uses Session Traversal Utilities for NAT (STUN) [RFC5389] and
Traversal Using Relays around NAT (TURN) [I-D.ietf-behave-turn]
protocols to achieve a reliable NAT traversal solution.
The benefit of using ICE and STUN/TURN is that one can re-use the NAT
traversal infrastructure already available in the Internet, such as
STUN and TURN servers. Also, some middleboxes may be STUN-aware and
could be able to do something "smart" when they see STUN being used
for NAT traversal. However, implementing a full ICE/STUN/TURN
protocol stack results in a considerable amount of effort and code
which could be avoided by re-using and extending HIP messages and
state machines for the same purpose. Thus, this document specifies a
new NAT traversal mode that uses HIP messages instead of STUN for the
connectivity checks, keepalives, and data relaying.
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 [RFC2119].
This document uses the same terminology as
[I-D.ietf-hip-nat-traversal] and the following:
HIP data relay:
A host that forwards HIP data packets, such as Encapsulating
Security Payload (ESP) [RFC5202], between two hosts.
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Registered host:
A host that has registered for a relaying service with a HIP data
relay.
3. Protocol Description
This section describes the normative behavior of the protocol
extension. Most of the procedures are similar to what is defined in
[I-D.ietf-hip-nat-traversal] but with different, or additional,
parameter types and values. In addition, a new type of relaying
server, HIP data relay, is specified.
3.1. Relay Registration
Relay registration procedure for HIP signaling is identical to the
one specified in Section 4.1 of [I-D.ietf-hip-nat-traversal].
However, a host MAY also register for UDP encapsulated ESP relaying
using Registration Type value RELAY_UDP_ESP (value 3).
If the HIP relay server supports relaying of UDP encapsulated ESP,
the host is allowed to register for data relaying service (see
Section 3.2), and the relay has relaying resources (free port
numbers, bandwidth, etc.) available, the relay opens a UDP port on
one of its addresses and signals the address and port to the
registering host using the RELAYED_ADDRESS parameter (see Section 4.1
for details). If the relay would accept the data relaying request
but does not have enough resources to provide data relaying service,
it MUST reject the request with Failure Type 2 (Insufficient
resources).
The registered host MUST maintain an active HIP association with the
data relay as long as it requires the data relaying service. When
the HIP association is closed (or times out), or the registration
lifetime passes without the registered host refreshing the
registration, the data relay MUST stop relaying packets for that host
and close the corresponding UDP port.
The data relay MAY use the same relayed address and port for multiple
registered hosts, but since this can cause problems with stateful
firewalls (see Section 5) it is NOT RECOMMENDED.
3.2. Registration Authentication
If the HIP data relay knows the Host Identities (HIs) of all the
hosts that are allowed to use the relaying service, it SHOULD reject
registrations from unknown hosts. However, since it may be
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unfeasible to pre-configure the relay with all the HIs, the relay
SHOULD also support HIP certificates [I-D.ietf-hip-cert] to allow for
certificate based authentication.
When a host wants to register with a HIP data relay, it SHOULD check
if it has a suitable certificate for authenticating with the relay.
How the suitability is determined and how the certificates are
obtained is out of scope for this document. If the host has one or
more suitable certificates, the host SHOULD include them (or just the
most suitable one) in a CERT parameter to the HIP packet along with
the REG_REQUEST parameter. If the host does not have any suitable
certificates, it SHOULD send the registration request without the
CERT parameter to test whether the relay accepts the request based on
the host's identity.
When a relay receives a HIP packet with a REG_REQUEST parameter, and
it requires authentication for at least one of the Registration Types
listed in the REG_REQUEST parameter, it MUST first check whether the
HI of the registering host is in the allowed list for all the
Registration Types in the REG_REQUEST parameter. If the host is in
the allowed list (or the relay does not require any authentication),
the relay MUST proceed with the registration.
If the host was not in the allowed list and the relay requires hosts
to authenticate, the relay MUST check whether the packet also
contains a CERT parameter. If the packet does not contain a CERT
parameter, the server MUST reject the registrations requiring
authentication with Failure Type 0 (Registration requires additional
credentials) [RFC5203]. If the certificate is valid and accepted
(issued for the registering host and signed by a trusted issuer), the
relay MUST proceed with the registration. If the certificate in the
parameter is not accepted, the relay MUST reject the corresponding
registrations with Failure Type 3 (Invalid certificate).
3.3. Forwarding Rules and Permissions
The HIP data relay uses a similar permission model as a TURN server:
before any ESP data packets sent by a peer are forwarded, a
permission must be set for the peer's address. The permissions also
install a forwarding rule, similar to TURN's channels, based on the
Security Parameter Index (SPI) values in the ESP packets.
Permissions are not required for the connectivity checks, but if a
relayed address is selected to be used for data, the registered host
MUST send an UPDATE message with a PEER_PERMISSION parameter with the
address of the peer and the outbound and inbound SPI values the host
is using with this peer.
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When a data relay receives an UPDATE with a PEER_PERMISSION
parameter, it MUST check if the sender of the UPDATE is registered
for data relaying service, and drop the UPDATE if the host was not
registered. If the host was registered, the relay checks if there is
a permission with matching information (address, protocol, port and
SPI values). If there is no such permission, a new permission is
created and its lifetime is set to 5 minutes. If an identical
permission already existed, it is refreshed by setting the lifetime
to 5 minutes. A registered host SHOULD refresh permissions roughly 1
minute before the expiration if the permission is still needed.
3.4. Relaying UDP Encapsulated Data and Control Packets
When a HIP data relay accepts to relay UDP encapsulated data, it
opens a UDP port (relayed address) for this purpose as described in
Section 3.1. If the data relay receives a UDP encapsulated HIP
control packet on that port, it MUST forward the packet to the
registered host and add a RELAY_FROM parameter to the packet as if
the data relay was acting as a HIP relay server
[I-D.ietf-hip-nat-traversal].
When a host wants to send a HIP control packet (such as a
connectivity check packet) to a peer via the data relay, it MUST add
a RELAY_TO parameter containing the peer's address to the packet and
send it to the data relay's address. The data relay MUST send the
packet to the peer's address from the relayed address.
If the data relay receives a UDP packet that is not a HIP control
packet to the relayed address, it MUST check whether there is a
permission set for the peer the packet is coming from (i.e., the
sender's address and SPI value matches to an installed permission),
and if there is, it MUST forward the packet to the registered host
that created the permission. Packets without a permission MUST be
dropped silently.
When a host wants to send a UDP encapsulated ESP packet to a peer via
the data relay, it MUST have an active permission at the data relay
for the peer with the outbound SPI value it is using. The host MUST
send the UDP encapsulated ESP packet to the data relay's address.
When the data relay receives a UDP encapsulated ESP packet from a
registered host, it MUST check whether there exists a permission for
that outbound SPI value. If such permission exists, the packet MUST
be forwarded to the address that was registered for the SPI value.
If no permission exists, the packet is dropped.
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3.5. Candidate Gathering
A host needs to gather a set of address candidates before starting
the connectivity checks. One server reflexive candidate can be
discovered during the registration with the HIP relay server from the
REG_FROM parameter.
If a host has more than one network interface, additional server
reflexive candidates can be discovered by sending registration
requests with Registration Type CANDIDATE_DISCOVERY (value 4) from
each of the interfaces to a HIP relay server. When a HIP relay
server receives a registration request with CANDIDATE_DISCOVERY type,
it MUST add a REG_FROM parameter, containing the same information as
if this was a relay registration, to the response. This request type
SHOULD NOT create any state at the HIP relay server.
It is RECOMMENDED that the host also obtains a relayed candidate from
a HIP data relay as described in Section 3.1.
Gathering of candidates MAY also be performed like specified in
Section 4.2 of [I-D.ietf-hip-nat-traversal] if STUN and TURN servers
are available, or if the host has just a single interface and there
are no TURN or HIP data relay servers available.
3.6. Base Exchange via HIP Relay Server
The Base Exchange is performed as described in Section 4.5 of
[I-D.ietf-hip-nat-traversal], except that "ICE candidates" are
replaced by the candidates gathered using procedures described in
Section 3.5
3.7. Native NAT Traversal Mode Negotiation
A host implementing this specification can signal the support for the
native HIP NAT traversal mode by adding ICE-HIP-UDP NAT traversal
mode (value 3) in the NAT_TRAVERSAL_MODE [I-D.ietf-hip-nat-traversal]
parameter. If this mode is supported by both endpoints, and is the
most preferred mode out of the all supported modes, further NAT
traversal procedures are performed as specified in this document.
3.8. Connectivity Check Pacing Negotiation
Since the NAT traversal mode specified in this document utilizes
connectivity checks, the check pacing negotiation MUST be performed
as specified in Section 4.4 of [I-D.ietf-hip-nat-traversal]. New
connectivity check transactions MUST NOT be started faster than once
every Ta (the value negotiated with the TRANSACTION_PACING
parameter).
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3.9. Connectivity Checks
The connectivity checks are performed as described in Section 4.6 of
[I-D.ietf-hip-nat-traversal] but instead of STUN packets, the
connectivity checks are HIP UPDATE packets. See Section 4.3 for
parameter details.
As defined in [I-D.ietf-hip-nat-traversal], both hosts MUST form a
priority ordered checklist and start check transactions every Ta
milliseconds as long as the checks are running and there are
candidate pairs whose tests have not started. The retransmission
timeout (RTO) for the connectivity check UPDATE packets MUST be
calculated as defined in Section 4.6 of [I-D.ietf-hip-nat-traversal].
All connectivity check request packets MUST contain a
CANDIDATE_PRIORITY parameter with the priority value that would be
assigned to a peer reflexive candidate if one was learned from this
check. The UPDATE packets that acknowledge a connectivity check
requests MUST be sent from the same address that received the check
and to the same address where the check was received from.
The acknowledgment UPDATE packets MUST contain a MAPPED_ADDRESS
parameter with the port, protocol, and IP address of the address
where the connectivity check request was received from.
After a working candidate pair, or pairs, have been discovered, the
controlling host MUST conclude the checks by nominating the highest
priority candidate pair for use. The pair MUST be nominated by
sending an ESP packet on the selected pair. If the controlling host
does not have any data to send, it SHOULD send an ICMP echo request
using the nominated pair to signal to the controlled host that it can
stop checks and start using the nominated pair.
If the connectivity checks failed the hosts SHOULD notify each other
about the failure with a CONNECTIVITY_CHECKS_FAILED NOTIFY packet.
3.10. NAT Keepalives
To keep the NAT bindings towards the HIP relay server and the HIP
data relay alive, if a registered host has not sent any data or
control messages to the relay for 15 seconds, it MUST send a HIP
NOTIFY packet to the relay. Likewise, if the host has not sent any
data to a host it has security association and has run connectivity
checks with, it MUST send either a HIP NOTIFY packet or an ICMP echo
request using the same locators as the security association is using.
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3.11. Handling Conflicting SPI Values
Since the HIP data relay determines from the SPI value to which peer
an ESP packet should be forwarded, the outbound SPI values need to be
unique for each relayed address registration. Thus, if a registered
host detects that a peer would use an SPI value that is already used
with another peer via the relay, it MUST NOT select the relayed
address for use. The host MAY restart the base exchange to avoid a
conflict or it MAY refrain from using the relayed candidate for the
connectivity checks.
Since the SPI space is 32 bits and the SPI values should be random,
the probability for a conflicting SPI value is fairly small.
However, a host with many peers MAY decrease the odds of a conflict
by registering more than one relayed address using different local
addresses.
4. Packet Formats
The following subsections define the parameter and packet encodings
for the new HIP parameters used for NAT traversal. UDP encapsulation
of the HIP and ESP packets and format of the other required
parameters is specified in Section 5 of [I-D.ietf-hip-nat-traversal].
4.1. RELAYED_ADDRESS and MAPPED_ADDRESS Parameters
The format of the RELAYED_ADDRESS and MAPPED_ADDRESS parameters
(Figure 1) is identical to REG_FROM, RELAY_FROM and RELAY_TO
parameters. This document specifies only use of UDP relaying and
thus only protocol 17 is allowed. However, future documents may
specify support for other protocols.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port | Protocol | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type [TBD by IANA; 952]
Length 20
Port the UDP port number
Protocol IANA assigned, Internet Protocol number (17 for UDP)
Reserved reserved for future use; zero when sent, ignored
when received
Address an IPv6 address or an IPv4 address in "IPv4-Mapped
IPv6 address" format
Figure 1: Format of the RELAYED_ADDRESS and MAPPED_ADDRESS Parameters
4.2. PEER_PERMISSION Parameter
The format of the PEER_PERMISSION parameter is shown in Figure 2.
The parameter is used for setting up and refreshing forwarding rules
and permissions at the data relay for data packets. The parameter
contains one or more sets of Port, Protocol, Address, Outbound SPI,
and Inbound SPI values. One set defines a rule for one peer address.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port | Protocol | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OSPI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ISPI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| ... |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type [TBD by IANA; 1020]
Length length in octets, excluding Type and Length
Port the transport layer (UDP) port number
Protocol IANA assigned, Internet Protocol number (17 for UDP)
Reserved reserved for future use; zero when sent, ignored
when received
Address an IPv6 address, or an IPv4 address in "IPv4-Mapped
IPv6 address" format, of the peer
OSPI the outbound SPI value the registered host is using for
the peer with the Address and Port
ISPI the inbound SPI value the registered host is using for
the peer with the Address and Port
Figure 2: Format of the PEER_PERMISSION Parameter
4.3. HIP Connectivity Check Packets
The connectivity request messages are HIP UPDATE packets with
CANDIDATE_PRIORITY parameter (Figure 3). Response UPDATE packets
contain a MAPPED_ADDRESS parameter (Figure 1).
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Priority |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type [TBD by IANA; 954]
Length 4
Priority the priority of a peer reflexive candidate
Figure 3: Format of the CANDIDATE_PRIORITY Parameter
5. Security Considerations
If the data relay uses the same relayed address and port for multiple
registered hosts, it appears to all the peers, and their firewalls,
that all the registered hosts using the relay are at the same
address. Thus, a stateful firewall may allow packets pass from hosts
that would not normally be able to send packets to a peer behind the
firewall. Therefore, a HIP data relay SHOULD NOT re-use the port
numbers. If port numbers need to be re-used, the relay SHOULD have a
sufficiently large pool of port numbers and select ports from the
pool randomly to decrease the chances of a registered host obtaining
the same address that a certain other host is using.
6. Acknowledgements
This document re-uses many of the ideas proposed in various earlier
HIP NAT traversal related drafts by Miika Komu, Simon Schuetz, Martin
Stiemerling, Pekka Nikander, Marcelo Bagnulo, Vivien Schmitt, Abhinav
Pathak, Lars Eggert, Thomas Henderson, Hannes Tschofenig, and Philip
Matthews.
7. IANA Considerations
This section is to be interpreted according to [RFC5226].
This document updates the IANA Registry for HIP Parameter Types
[RFC5201] by assigning new HIP Parameter Type value for the new HIP
Parameter: RELAYED_ADDRESS (defined in Section 4.1).
This document also updates the IANA Registry for HIP NAT traversal
modes [I-D.ietf-hip-nat-traversal] by assigning value for the NAT
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traversal mode ICE-HIP-UDP (defined in Section 3.7).
This document defines additional registration types for the HIP
Registration Extension [RFC5203] that allow registering with a HIP
relay server for ESP relaying service: RELAY_UDP_ESP (defined in
Section 3.1); and performing server reflexive candidate discovery:
CANDIDATE_DISCOVERY (defined in Section 3.5).
The IANA Registry for HIP Registration Failure Types is updated with
new Failure Types "Insufficient resources" (defined in Section 3.1)
and "Invalid certificate" (defined in Section 3.2).
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5201] Moskowitz, R., Nikander, P., Jokela, P., and T. Henderson,
"Host Identity Protocol", RFC 5201, April 2008.
[RFC5202] Jokela, P., Moskowitz, R., and P. Nikander, "Using the
Encapsulating Security Payload (ESP) Transport Format with
the Host Identity Protocol (HIP)", RFC 5202, April 2008.
[RFC5203] Laganier, J., Koponen, T., and L. Eggert, "Host Identity
Protocol (HIP) Registration Extension", RFC 5203,
April 2008.
[RFC5207] Stiemerling, M., Quittek, J., and L. Eggert, "NAT and
Firewall Traversal Issues of Host Identity Protocol (HIP)
Communication", RFC 5207, April 2008.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC5389] Rosenberg, J., Mahy, R., Matthews, P., and D. Wing,
"Session Traversal Utilities for NAT (STUN)", RFC 5389,
October 2008.
[I-D.ietf-hip-nat-traversal]
Komu, M., Henderson, T., Tschofenig, H., Melen, J., and A.
Keranen, "Basic HIP Extensions for Traversal of Network
Address Translators", draft-ietf-hip-nat-traversal-09
(work in progress), October 2009.
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[I-D.ietf-mmusic-ice]
Rosenberg, J., "Interactive Connectivity Establishment
(ICE): A Protocol for Network Address Translator (NAT)
Traversal for Offer/Answer Protocols",
draft-ietf-mmusic-ice-19 (work in progress), October 2007.
[I-D.ietf-hip-cert]
Heer, T. and S. Varjonen, "HIP Certificates",
draft-ietf-hip-cert-02 (work in progress), October 2009.
8.2. Informative References
[I-D.ietf-behave-turn]
Rosenberg, J., Mahy, R., and P. Matthews, "Traversal Using
Relays around NAT (TURN): Relay Extensions to Session
Traversal Utilities for NAT (STUN)",
draft-ietf-behave-turn-16 (work in progress), July 2009.
Authors' Addresses
Ari Keranen
Ericsson
Hirsalantie 11
02420 Jorvas
Finland
Email: Ari.Keranen@ericsson.com
Jan Melen
Ericsson
Hirsalantie 11
02420 Jorvas
Finland
Email: Jan.Melen@ericsson.com
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