doc: Add RFC documents

1 files changed, 619 insertions, 0 deletions

diff --git a/doc/rfc/rfc3105.txt b/doc/rfc/rfc3105.txt
new file mode 100644
index 0000000..70eac41
--- /dev/null
+++ b/doc/rfc/rfc3105.txt
@@ -0,0 +1,619 @@
+
+
+
+
+
+
+Network Working Group                                           J. Kempf
+Request for Comments: 3105                           NTT DoCoMo USA Labs
+Category: Experimental                                     G. Montenegro
+                                                        Sun Microsystems
+                                                            October 2001
+
+                    Finding an RSIP Server with SLP
+
+Status of this Memo
+
+   This memo defines an Experimental Protocol for the Internet
+   community.  It does not specify an Internet standard of any kind.
+   Discussion and suggestions for improvement are requested.
+   Distribution of this memo is unlimited.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2001).  All Rights Reserved.
+
+IESG Note
+
+   The IESG notes that the set of documents describing the RSIP
+   technology imply significant host and gateway changes for a complete
+   implementation.  In addition, the floating of port numbers can cause
+   problems for some applications, preventing an RSIP-enabled host from
+   interoperating transparently with existing applications in some cases
+   (e.g., IPsec).  Finally, there may be significant operational
+   complexities associated with using RSIP.  Some of these and other
+   complications are outlined in section 6 of the RFC 3102, as well as
+   in the Appendices of RFC 3104.  Accordingly, the costs and benefits
+   of using RSIP should be carefully weighed against other means of
+   relieving address shortage.
+
+Abstract
+
+   This document contains an SLP service type template that describes
+   the advertisements made by RSIP servers for their services.  Service
+   Location Protocol (SLP) is an IETF standards track protocol
+   specifically designed to allow clients to find servers offering
+   particular services.  Since RSIP (Realm Specific IP) clients require
+   a mechanism to discover RSIP servers, SLP is a natural match for a
+   solution.  The service type template is the basis for an Internet
+   Assigned Numbers Authority (IANA) standard definition of the
+   advertisements offered by RSIP servers, an important step toward
+   interoperability.
+
+
+
+
+
+
+Kempf & Montenegro            Experimental                      [Page 1]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+Table of Contents
+
+   1.  Introduction ...............................................  2
+   2.  Notation Conventions .......................................  2
+   3.  Terminology ................................................  2
+   4.  Using SLP for RSIP Service Discovery .......................  3
+   5.  Using Scopes for Server Provisioning .......................  4
+   6.  Load Balancing .............................................  6
+   7.  The RSIP Service Type Template .............................  7
+   8.  Security Considerations ....................................  9
+   9.  Summary ....................................................  9
+   References .....................................................  9
+   Authors' Addresses ............................................. 10
+   Full Copyright Statement ....................................... 11
+
+1. Introduction
+
+   Realm Specific IP (RSIP) [7] enables an RSIP client in one realm to
+   borrow addresses and other resources from another realm.  It does so
+   by engaging in an RSIP protocol [1] exchange with an RSIP server.
+   The RSIP protocol requires the RSIP server to have a permanent
+   presence on both realms.
+
+   There are a variety of traditional ways an RSIP client could go about
+   locating the appropriate RSIP server.  However, Service Location
+   Protocol (SLP) [2][11] is an IETF standards track protocol
+   specifically designed to facilitate location of services and their
+   servers by clients.  SLP provides a number of features that simplify
+   locating RSIP servers.  In this document, we describe how RSIP
+   clients can use SLP to discover RSIP servers.
+
+2.  Notation Conventions
+
+   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 [4].
+
+3.  Terminology
+
+   We reproduce here some SLP terminology from [2] for readers
+   unfamiliar with SLP.
+
+   User Agent (UA)
+
+      A process working on the user's behalf to establish contact with
+      some service.  The UA retrieves service information from the
+      Service Agents or Directory Agents.
+
+
+
+
+Kempf & Montenegro            Experimental                      [Page 2]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+   Service Agent (SA)
+
+      A process working on behalf of one or more services to advertise
+      the services and their capabilities.
+
+   Directory Agent (DA)
+
+      A process which collects service advertisements.  There can only
+      be one DA present per given host.
+
+   Scope
+
+      A set of services, typically making up a logical administrative
+      group.
+
+   Service Advertisement
+
+      A URL, attributes, and a lifetime (indicating how long the
+      advertisement is valid), providing service access information and
+      capabilities description for a particular service.
+
+4.  Using SLP for RSIP Service Discovery
+
+   SLP provides the framework in which RSIP clients and servers make
+   contact.  Here is a description of how an RSIP server and client find
+   each other using SLP:
+
+   1. The RSIP server implements a SLP SA while the RSIP client
+      implements an SLP UA.
+
+   2. The RSIP SA constructs a service advertisement consisting of a
+      service URL, attributes and a lifetime.  The URL has service type
+      "service:rsip", and attributes defined according to the template
+      in Section 7.
+
+   3. If an SLP DA is found, the SA contacts the DA and registers the
+      advertisement.  If no DA is found, the SA maintains the
+      advertisement itself, answering multicast UA queries directly.
+
+   4. When the RSIP client requires contact information for an RSIP
+      server, the UA either contacts the DA using unicast or the SA
+      using multicast.  The UA includes a query based on the attributes
+      to indicate the characteristics of the server it requires.
+
+   5. Once the UA has the host name or address of the RSIP server as
+      well as the port number, it can begin negotiation using the RSIP
+      protocol.
+
+
+
+
+Kempf & Montenegro            Experimental                      [Page 3]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+   This procedure is exactly the same for any client/server pair
+   implementing SLP and is not specific to RSIP.
+
+   Many protocols use a variety of traditional methods for service
+   discovery.  These methods include static configuration, purpose-build
+   protocols for discovery, special features in the protocol itself, DNS
+   SRV RRs [5], or DHCP [6].  SLP provides a number of advantages over
+   these traditional methods:
+
+   1. Discovery of services using SLP is dynamic, whereas many of the
+      traditional methods only allow static or weakly dynamic (i.e.,
+      difficult to update) discovery.  Clients only discover services
+      that are actually active with SLP.  Furthermore, if subsequent to
+      initial discovery a server goes down, the client can reissue an
+      SLP query and obtain a new server.  On the server side, no
+      databases must be updated to provide dynamic discovery, the
+      servers advertise themselves.
+
+   2. SLP requires no third party configuration.  Only the server
+      offering the service and the client seeking it are required to
+      know the details for the particular service type.
+
+   3. SLP allows clients to specify the attributes describing the
+      desired server.  A client discovers servers that meet a set of
+      specific requirements.  This reduces the amount of network traffic
+      involved in selecting a server when many possible choices are
+      available.
+
+   4. SLP contains a number of scaling mechanisms (DAs, scopes,
+      multicast convergence algorithm), that facilitate deployment in
+      large enterprise networks as well as in smaller networks.
+
+5.  Using Scopes for Server Provisioning
+
+   One particular design feature of SLP that is useful for RSIP is
+   scopes.  Scopes in SLP are a mechanism for provisioning access to
+   particular service advertisements.  An administrator assigns UAs and
+   SAs to particular scopes to assure that UAs only find SAs in those
+   scopes.  Scopes are not an access control mechanism for the service
+   itself, however.  UAs from outside the scope can still access
+   services in a particular scope (unless the service itself provides
+   for access control), they just won't be able to find the services
+   using SLP.
+
+   Scopes are useful for RSIP service advertisement provisioning because
+   they allow a system administrator to tie particular RSIP clients to
+   specific RSIP servers.  For example, consider the network
+   architecture described in Section 4.2.1 of [7].  RSIP clients are
+
+
+
+Kempf & Montenegro            Experimental                      [Page 4]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+   recommended to find "the nearest" RSIP server, but exactly how that
+   should be arranged is left unspecified.  SLP provides a way for
+   system administrators to precisely specify which realm an RSIP client
+   resides in, by tying the realm to an SLP scope.  The diagram from
+   Section 14.1 is reproduced here, with SLP scopes included to
+   illustrate how clients could be directed to the right RSIP servers.
+
+                                +-----------+
+                                |           |
+                                |   RSIP    |
+                                |  server   +---- 10.0.0.0/8
+                                |     B     |   SLP Scope: B
+                                |           |
+                                +-----+-----+
+                                      |
+                                      | 10.0.1.0/24
+                       +-----------+  | (149.112.240.0/25)
+                       |           |  |
+       149.112.240.0/24|    RSIP   +--+
+       ----------------+   server  |    SLP Scope: A
+                       |      A    +--+
+                       |           |  |
+                       +-----------+  | 10.0.2.0/24
+                                      | (149.112.240.128/25)
+                                      |
+                                +-----+-----+
+                                |           |
+                                |   RSIP    |
+                                |  server   +---- 10.0.0.0/8
+                                |     C     |     SLP Scope: C
+                                |           |
+                                +-----------+
+
+   Clients on the upper 10.0.0.0/8 network are configured to use SLP
+   scope B, while clients on the lower 10.0.0.0/8 network are configured
+   to use SLP scope C.  RSIP servers B and C (as clients of server A)
+   use SLP to locate RSIP server A, as do other RSIP clients on the
+   10.0.1.0/24 and 10.0.2.0/24 subnets.  Within these two subnets, all
+   clients have their scopes configured to be A.
+
+   Note that specifying a particular SLP scope for RSIP clients does not
+   restrict the SLP scope for other services advertised by SLP.  SLP UAs
+   can be configured for multiple scopes, so the scope configured for
+   printing may be different from the scope configured for RSIP service.
+
+   Since SLP scopes are configured through a DHCP option [8], along with
+   the IP address, system administrators can easily switch a cluster of
+   machines from one realm to another by simply changing the scope and
+
+
+
+Kempf & Montenegro            Experimental                      [Page 5]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+   IP address assignments on the DHCP server.  For example, in the above
+   architecture, suppose a system administrator wanted to remove RSIP
+   server B so that clients on the upper 10.0.0.0/8 subnet were directly
+   on subnet 10.0.1.0/24.  These clients now communicate with RSIP
+   server A.  By simply changing the address assignments and scope
+   configuration of these clients on the DHCP server, the realm can be
+   effectively switched.
+
+6.  Load Balancing
+
+   While SLP itself contains no specific provision for load balancing,
+   load balancing can easily be implemented using SLP.  The only
+   requirement is that the service type template specify an attribute
+   indicating server load.  In the case of RSIP, the service type
+   template in Section 7  contains such an attribute.  The attribute
+   indicates the number of RSIP client sessions currently being
+   supported by the server.
+
+   In order to perform load balancing, the RSIP server must update its
+   service advertisement periodically as new connections are accepted.
+   An RSIP client seeking to find the server having the lightest load
+   performs the following series of SLP operations.
+
+   1. As in Section 4, the client issues an SLP service request and
+      collects all the returned service URLs.
+
+   2. For each service URL, the client performs an SLP attribute request
+      for the attribute LOAD.  The integer load figures are returned.
+
+   3. The client sorts through the returned load figures and selects the
+      URL having the least number of connections.  The client
+      establishes its RSIP session with that server.
+
+   Because of network delays, this procedure does not guarantee that a
+   client will always obtain a connection with the lightest loaded
+   server, but it does provide a high probability that the selected
+   server is more lightly loaded.
+
+   A similar procedure is used in [9] to load balance access to TN3270E
+   telnet servers.
+
+
+
+
+
+
+
+
+
+
+
+Kempf & Montenegro            Experimental                      [Page 6]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+7.  The RSIP Service Type Template
+
+   Name of submitters: James Kempf <james@docomolabs-usa.com>
+                       Gabriel Montenegro <gab@sun.com>
+
+   Language of service template: en
+
+   Security Considerations:
+      RSIP clients can use Service Location Protocol to find RSIP
+      servers having particular security characteristics.  If secure
+      access to such information is required, SLP security should be
+      used.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Kempf & Montenegro            Experimental                      [Page 7]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+Template text:
+----------------------template begins here -------------------------
+template-type = rsip
+
+template-version = 0.0
+
+template-description=
+   The service:rsip type provides advertisements for clients seeing
+   realm-specific IP (RSIP) servers.  RSIP servers use the Realm
+   Specific IP protocol to manage addresses and other resources
+   from one realm on behalf of a client in another realm.
+
+template-url-syntax=
+   ;No additional URL path information required.  An example service
+   ;URL for an RSIP server is: service:rsip://gateway.mydomain:4455
+
+ipsec-support = BOOLEAN O
+   #True if the server supports IPSEC as per [10]
+
+ike-support = BOOLEAN O
+   #True if the server supports IKE as per [10]
+
+tunnel-type = STRING L M O
+IP-IP
+   #The tunneling methods supported by the RSIP server.  Clients
+   #should include this attribute in a query so that they obtain a
+   #server offering a tunneling method for which they have
+   #support.  Default is IP-IP.  The values are currently
+   #restricted to IP-IP, L2TP, GRE and NONE.  A server can support
+   #multiple tunnel types.
+IP-IP,L2TP,GRE,NONE
+
+transport = STRING L M O
+TCP
+   #Transport used by the RSIP protocol itself.
+TCP,UDP
+
+load = INTEGER O
+   #If the server supports load balancing, this attribute should be
+   #set to an integer from 0 to 100.  0 is the lowest indication of
+   #load and 100 the highest.  Clients can query for this attribute
+   #and obtain load information, from which they can make an
+   #intelligent decision about which server to use.
+----------------------template ends here ---------------------------
+
+
+
+
+
+
+
+Kempf & Montenegro            Experimental                      [Page 8]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+8.  Security Considerations
+
+   Service type templates provide information that is used to interpret
+   information obtained by clients through SLP.  If the RSIP template is
+   modified or if a false template is distributed, RSIP servers may not
+   correctly register themselves, or RSIP clients may not be able to
+   interpret service information.
+
+   SLP provides an authentication mechanism for UAs to assure that
+   service advertisements only come from trusted SAs [2].  If trust is
+   an issue, particularly with respect to the information sought by the
+   client about IPSEC and IKE support, then SLP authentication should be
+   enabled in the network.
+
+9.  Summary
+
+   This document describes how SLP can be used by RSIP clients to find
+   RSIP servers.  A service type template for an RSIP SLP service type
+   is presented.  In addition, a few techniques for provisioning access
+   to service advertisements for particular gateway servers, and for
+   load balancing using SLP were provided.  The result should allow RSIP
+   service provisioning that is considerably more dynamic and robust
+   than when traditional service discovery mechanisms are used.
+
+References
+
+   [1]  Borella, M., Grabelsky, D., Lo, J. and K. Taniguchi, "Realm
+        Specific IP: Protocol Specification", RFC 3103, April 2001.
+
+   [2]  Guttman, E., Perkins, C., Veizades, J. and M. Day, "Service
+        Location Protocol, version 2", RFC 2608, July 1999.
+
+   [3]  Guttman, E, Perkins, C. and J. Kempf, "Service Templates and
+        service: Schemes", RFC 2609, July 1999.
+
+   [4]  Bradner, S., "Key Words for Use in RFCs to Indicate Requirement
+        Levels", BCP 14, RFC 2119, March 1997.
+
+   [5]  Gulbrandsen, A. and P. Vixie, "A DNS RR for specifying the
+        location of services (DNS SRV)", RFC 2052, October 1996.
+
+   [6]  Droms, R., "Dynamic Host Configuration Protocol", RFC 2131,
+        March 1997.
+
+   [7]  Borella, M., Lo, J., Grabelsky, D. and G. Montenegro, "Realm
+        Specific IP: Framework", RFC 3102, October 2001.
+
+
+
+
+
+Kempf & Montenegro            Experimental                      [Page 9]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+   [8]  Perkins, C. and E. Guttman, "DHCP Options for Service Location
+        Protocol", RFC 2610, July 1999.
+
+   [9]  Naugle, J., Kasthurirangan, K. and G. Ledford, "TN3270E Service
+        Location and Session Balancing", RFC 3049, January 2001.
+
+   [10] Montenegro, G. and M. Borella, "RSIP Support for End-to-end
+        IPSEC", RFC 3104, October 2001.
+
+   [11] E. Guttman, "Service Location Protocol: Automatic Discovery of
+        IP Network Services," IEEE Internet Computing, July/August 1999.
+        Available at: http://computer.org/internet/ic1999/w4toc.htm
+
+Authors' Addresses
+
+   Questions about this document may be directed to:
+
+   James Kempf
+   NTT DoCoMo USA Labs
+   181 Metro Drive, Suite 300
+   San Jose, CA
+   95110
+
+   Phone: 408-451-4711
+   Email: james@docomolabs-usa.com
+
+
+   Gabriel E. Montenegro
+   Sun Microsystems
+   Laboratories, Europe
+   29, chemin du Vieux Chene
+   38240 Meylan
+   FRANCE
+
+   Phone: +33 476 18 80 45
+   EMail: gab@sun.com
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Kempf & Montenegro            Experimental                     [Page 10]
+
+RFC 3105            Finding an RSIP Server with SLP         October 2001
+
+
+Full Copyright Statement
+
+   Copyright (C) The Internet Society (2001).  All Rights Reserved.
+
+   This document and translations of it may be copied and furnished to
+   others, and derivative works that comment on or otherwise explain it
+   or assist in its implementation may be prepared, copied, published
+   and distributed, in whole or in part, without restriction of any
+   kind, provided that the above copyright notice and this paragraph are
+   included on all such copies and derivative works.  However, this
+   document itself may not be modified in any way, such as by removing
+   the copyright notice or references to the Internet Society or other
+   Internet organizations, except as needed for the purpose of
+   developing Internet standards in which case the procedures for
+   copyrights defined in the Internet Standards process must be
+   followed, or as required to translate it into languages other than
+   English.
+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assigns.
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+Acknowledgement
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Kempf & Montenegro            Experimental                     [Page 11]
+