(12) United States Patent
`Guerin et al.
`
`I lllll llllllll Ill lllll lllll lllll lllll lllll 111111111111111111111111111111111
`US006243754Bl
`US 6,243,754 Bl
`Jun.5,2001
`
`(10) Patent No.:
`(45) Date of Patent:
`
`(54) DYNAMIC SELECTION OF NETWORK
`PROVIDERS
`
`(75)
`
`Inventors: Roch A. Guerin, Yorktown Heights;
`Arvind Krishna, Somers; Vinod
`Gerard John Peris, Chappaqua;
`Dinesh Chandra Verma, Millwood, all
`of NY (US)
`
`(73) Assignee: International Business Machines
`Corporation, Armonk, NY (US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/227,769
`
`(22) Filed:
`
`Jan. 8, 1999
`
`Int. Cl.7 ...................................................... G06F 15/16
`(51)
`(52) U.S. Cl. .......................... 709/227; 709/225; 709/228;
`709/229; 709/238; 709/239
`(58) Field of Search ..................................... 709/225, 227,
`709/228, 229, 238, 239
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`5,845,073 * 12/1998 Carlin et al. ......................... 709/217
`5,862,490 * 1/1999 Sasuta et al.
`........................ 455/525
`5,933,490 * 8/1999 White et al. ......................... 379/221
`5,961,608 * 10/1999 Onosaka et al. ..................... 709/249
`5,970,477 * 10/1999 Roden .................................... 705/32
`5,987,498 * 11/1999 Athing et al. ........................ 709/203
`5,991,292 * 11/1999 Focsaneanu et al. ................ 370/352
`6,112,245 * 8/2000 Araujo et al. ........................ 709/228
`
`105
`
`6,119,162 * 9/2000 Li et al.
`............................... 709/227
`6,128,668 * 10/2000 Barber et al. ........................ 709/246
`6,145,002 * 11/2000 Srinivasan ............................ 709/225
`* cited by examiner
`Primary Examiner-Saleh Najjar
`(74) Attorney, Agent, or Firm-Louis P. Herzberg
`ABSTRACT
`
`(57)
`
`A method, apparatus and system is provided by which two
`or more cooperating end-users of the Internet and/or other
`network can dynamically select and use a single Internet or
`other network service provider (ISP) from among a multi(cid:173)
`tude of ISPs based on the application requirements. The
`service provider may be selected in a dynamic fashion. This
`overcomes the problem wherein traditionally most end(cid:173)
`users, whether they are individuals or organizations, are
`connected to the Internet or other network through a single
`Internet and/or other network service provider. However,
`users generally may have more than a single connection to
`the Internet and/or other network. In such cases the routing
`of traffic over these multiple connections is handled by IP
`routers based on the routing information that they exchange
`with their peers. This information is relatively static in
`nature and is typically based on the state of links that
`interconnect the different routers. The invention provides a
`mechanism for the end-user to take advantage of different
`rates or services that might be provided by competing
`Internet and/or other network service providers.
`Furthermore, there are cases where the choice of which
`provider to use depends on the application. Thus this inven(cid:173)
`tion enables cooperating users (or sites of an organization)
`to dynamically select different providers on an application
`by application basis.
`
`25 Claims, 4 Drawing Sheets
`
`101
`
`103
`
`SITE NETWORK
`
`ROUTER
`
`Cisco Systems, Inc.
`Exhibit 1006
`Page 1 of 10
`
`

`

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`119
`
`115
`
`SITE NETWORK
`
`ROUTER
`
`ROUTER
`
`SITE NETWORK
`
`103
`
`109
`
`101
`
`105
`
`FIG. 1
`
`Cisco Systems, Inc.
`Exhibit 1006
`Page 2 of 10
`
`

`

`U.S. Patent
`
`Jun.5,2001
`
`Sheet 2 of 4
`
`US 6,243,754 Bl
`
`FIG. 2A
`
`ESTABLISH CONTROL
`CHANNEL TO CALLED
`SITE
`
`SELECT PROVIDER TO
`BE USED
`
`COMMUNICATE
`SELECTION AND
`PARAMETERS TO
`CALLED SITE
`
`CALLED SITE
`RESPONDS WITH
`CONFIRMATION AND
`PARAMETERS
`
`OBTAIN
`CONFIRMATION FROM
`CALLED SITE
`
`ESTABLISH DATA
`CONNECTION
`
`ROUTE FORWARD
`DATA ON DATA
`CONNECTION
`
`203
`
`205
`
`207
`
`208
`
`209
`
`211
`
`213
`
`FIG. 28
`
`START
`
`217
`
`SEND CONFIRMATION
`OF CONTROL PATH TO
`ORIGINAL SITE
`
`ACCEPT DATA
`CONNECTION
`
`ROUTE REVERSE
`DATA ON DATA
`CONNECTION
`
`STOP
`
`225
`
`219
`
`221
`
`223
`
`Cisco Systems, Inc.
`Exhibit 1006
`Page 3 of 10
`
`

`

`U.S. Patent
`
`Jun.5,2001
`
`Sheet 3 of 4
`
`US 6,243,754 Bl
`
`301
`
`9.0.0.1
`
`FIG. 3
`
`307
`
`SECOND PROVIDER
`
`ROUTER A
`
`305
`
`5.0.0.2
`
`FIRST PROVIDER
`
`ROUTER B
`
`SITE B
`
`B 313
`
`Cisco Systems, Inc.
`Exhibit 1006
`Page 4 of 10
`
`

`

`U.S. Patent
`
`Jun.5,2001
`
`Sheet 4 of 4
`
`US 6,243,754 Bl
`
`r ________________________________ J ___ :
`I
`
`FIG. 4
`
`401
`
`(405
`
`PROVIDER SELECTOR MODULE
`
`f 407
`
`ORIGINATING SITE INTERFACE
`MODULE
`
`CALLED SITE INTERFACE
`MODULE
`
`I
`I
`
`I
`
`I
`
`I
`I
`
`409l
`
`DATA FORWARDING MODULE
`
`!
`
`I
`:_ ---
`
`---
`
`---
`
`---
`
`---
`
`---
`
`---
`
`---
`
`---
`
`---
`
`---
`
`:
`-_ J
`
`Cisco Systems, Inc.
`Exhibit 1006
`Page 5 of 10
`
`

`

`US 6,243,754 Bl
`
`1
`DYNAMIC SELECTION OF NETWORK
`PROVIDERS
`
`FIELD OF THE INVENTION
`This invention is directed to the field of computer net(cid:173)
`works. It is more particularly directed to networks wherein
`communication between two communicators may be
`accomplished using more than one network provider.
`
`2
`more cooperating end-users of the Internet and/or other
`network can dynamically select and use a single ISP from a
`multitude of ISPs based on the application requirements.
`It is another aspect of the present invention to present an
`5 apparatus for selection of the Internet and/or other network
`service provider in a dynamic fashion.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`10
`
`These and other objects, features, and advantages of the
`present invention will become apparent upon further con(cid:173)
`sideration of the following detailed description of the inven(cid:173)
`tion when read in conjunction with the drawing figures, in
`which:
`FIG. 1 shows an example of a block diagram of a network
`in which an ISP Selection scheme outlined in this invention
`can be used;
`FIG. 2(a) is a flow diagram that illustrates an example of
`steps taken when ISP selection is made in accordance with
`the present invention;
`FIG. 2(b) shows a set of steps corresponding to FIG. 2(a)
`that are executed by the router at the called site in accor(cid:173)
`dance with the present invention;
`FIG. 3 is a block diagram illustrating an example of
`25 network ISP selection in accordance with the present inven-
`tion; and
`FIG. 4 is a block diagram that describes an example of a
`structure of an apparatus which can be used to implement an
`30 ISP selection scheme in accordance with the present inven(cid:173)
`tion.
`
`BACKGROUND OF THE INVENTION
`Growth in the Internet and other network requirements
`have resulted in a proliferation of Internet Service Providers
`and other interconnection network providers. Both the Inter(cid:173)
`net Service Providers and the other interconnection network
`providers are herein referred to as ISPS. Each ISP offers 15
`connectivity to the ubiquitous Internet and/or other network
`for multiple corporations as well as individual users. Due to
`the large number of network providers, as well as the
`anticipated number of new network providers, some sites are
`likely to have connectivity to the Internet and/or other 20
`network via more than one ISP. The level of service provided
`by the different service providers may indeed vary widely
`from one ISP to another.
`As an example consider the case where two sites of an
`organization are connected to the Internet and/or other
`network through two different ISPs, namely ISP-A and
`ISP-B. It is quite conceivable that ISP-A guarantees a low
`delay but is rather expensive for its service, whereas ISP-B
`provides a cheaper service than ISP-A, but does not guar(cid:173)
`antee low delays. There may be some applications like voice
`that need low delay to be effective, whereas other applica(cid:173)
`tions like e-mail or file transfers are fairly tolerant to delays.
`In some cases the decision as to which ISP to use may
`further depend on the users individual preferences. With the
`current state of the art technology, the end-user is forced to 35
`choose a single ISP (in this case it is ISP-A or ISP-B) for
`routing traffic to any given destination. Even if the user is a
`multi-homed host with multiple connections to the Internet
`and/or other network the choice of which ISP to use is
`governed by the routing information exchanged by the 40
`routers in the Internet and/or other network. Typically the
`route chosen depends on the destination address in each
`packet and does not depend on the specific applications and
`their individual requirements.
`If the user desires the low delay guarantee provided by 45
`ISP-A in the above example it is generally not sufficient to
`simply direct its traffic onto the interface that is connected to
`ISP-A Each ISP is assigned ownership of a certain number
`of machine addresses in the Internet and/or other network
`the range of these machine addresses being known as th~ 50
`address space of the ISP. If the destination address belongs
`to the address space of ISP-B, then it is quite likely that the
`packet will cross-over from provider ISP-A to ISP-B
`prematurely, thereby rendering the delay guarantee of ISP-A
`null and void. One solution is for all of the end-hosts to have 55
`IP addresses in the address-spaces of each candidate ISP so
`that this cross-over does not take place. However, this
`solution does not scale well as there may be quite a few ISPs
`and thousands of individual host machines. An alternate
`solution is to translate the addresses at the network edges so 60
`that depending on the applications individual requirements
`an appropriate ISP and an address from its space is chosen
`for each connection.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`FIG. 1 shows an example of a network block diagram
`within which a method of this invention can be used. The
`network of FIG. 1 includes a plurality of small networks at
`multiple sites which are connected together by means of a
`backbone network provided by an ISP. The figure shows
`networks at two sites, 101 and 103. These are connected
`together by means of two Internet (and/or other network)
`Service Provider networks, 105 and 107. The characteristics
`of ISP networks 105 and 107 are assumed to be quite
`different. For example, it is assumed that ISP network 105
`provides an expensive but low-delay service between sites
`101 and 103, while ISP network 107 provides a cheaper but
`higher-delay service between the same sites. Internet
`addresses at site 101 or 103 may be allocated from the
`address space of network 105 or from the address space of
`network 107. The operator of networks 101 and 103 may
`also choose to allocate addresses from another address-space
`that they may have been allocated independent of networks
`105 or 107.
`The network at: site 101 is connected to the ISP network
`105 and 107 by means of a router 109. The router 109 is
`shown to have three interfaces. One interface 111 connects
`it to the ISP network 105. Another interface 113 connects it
`to the ISP network 107. A third interface 115 connects it to
`the local site network 101. Interface 111 has an address
`allocated in the address space of network 105, while inter(cid:173)
`face 113 has an address allocated in the address space of
`network 107. Interface 115 may have an address in the
`address-space of network 105 or network 107, or in an
`independent address-space. Similarly, network 103 is con-
`65 nected to ISP networks 105 and 107 by means of a second
`router 117 with three interfaces 119, 121and123. Interface
`121 has an address in the address space of network 105 and
`
`SUMMARY OF THE INVENTION
`Accordingly, it is an aspect of the present invention to
`present a method, apparatus and system by which two or
`
`Cisco Systems, Inc.
`Exhibit 1006
`Page 6 of 10
`
`

`

`US 6,243,754 Bl
`
`3
`connects the router 117 to network 105. Interface 123 has an
`address in the address space of network 107 and connects the
`router 119 to the network 107. Interface 119 connects the
`router 117 to the network 103 and may have an address in
`the address-space of network 105, network 107, or may have
`an address from an independent address space.
`In the network shown in FIG. 1, router 109 and/or 117
`need to select a specific provider from a number of providers
`to exchange a specific set of application data. In order to use
`a specific provider, the router at the originating site takes the
`steps shown in FIG. 2(a). The process is entered in step 201
`when the router has to determine the appropriate service
`provider to use for communication of application data to a
`remote called site. In step 203, the router at the originating
`site establishes a control channel to the router at the called 15
`site. After the establishment of the control channel, the two
`sites may exchange some control information such as the list
`of valid service providers at each site, and any performance
`or cost characteristics associated with the list of valid service
`providers. In step 205, the originating site selects an appro(cid:173)
`priate service provider from the different possible choices. A
`variety of criteria such as cost, quality of service, preestab(cid:173)
`lished business contracts etc. may be used for selecting the
`service provider. In step 207, the originating site commu(cid:173)
`nicates its selection of the service provider to the called site. 25
`Along with the choice of the provider, parameters such as a
`specific address in the domain of the selected provider,
`which would be used for data exchange, may be communi(cid:173)
`cated to the called site.
`In some embodiments optional steps 208 and 209 are
`implemented. In step 208 the called site responds with a
`confirmation and possibly some configuration parameters.
`The originating site waits for the receipt of this confirmation
`in step 209. The originating site then establishes its local
`data connection state in step 211. The local data connection 35
`contains information that can be used to route forward data
`to the called site. In step 213, the router at the originating site
`starts forwarding packets to the called site using the infor(cid:173)
`mation in the local data connection state. The procedure
`terminates in step 215.
`FIG. 2(b) shows a corresponding set of steps that are
`executed by the router at the called site. The router at the
`called site enters the process in step 217 until it receives a
`request for a control connection from an originating site. In
`step 219, the router accepts the control connection, and
`exchanges any control parameters with the originating site.
`In step 221, the router at the called site accepts a data
`connection and creates the local connection state for receiv(cid:173)
`ing data from the originating site.
`In one embodiment, the acceptance of the data connection
`in step 221 is a separate request from the originating site. In
`an alternate embodiment, acceptance is implied by the
`creation of the control connection. In step 223, the router at
`the called site starts to forward reverse direction data packets 55
`for the communication along the data connection established
`in step 221. The procedure terminates in step 225.
`When the originating site has to communicate with a
`second called site, it repeats steps 203-215 using a second
`control channel and a second data connection. A second 60
`control channel may be created to two different routers at the
`same called site. In some cases, the second called site and
`the first called site may be served by the same router. In other
`cases, the second called site and the first called site may be
`the same site.
`Variations to the steps outlined in FIG. 2 may be per(cid:173)
`formed when multiple data connections are being estab-
`
`4
`lished between two sites. For instance, the control channel
`need not always be created among two sites. The originating
`site can check to determine if a control channel already
`exists for the called site, and only creates a control channel
`if such a channel does not already exist.
`Data forwarding is generally accomplished by encapsu(cid:173)
`lating the original data packets into an outer packet or by
`network address translation. FIG. 3 shows a case where a
`first communicator 301 with an address of 9.0.0.1 at site A
`10 303 wishes to communicate with a second communicator
`313 with address of 10.0.0.2 at site B 311. Router-A 305 at
`site A303 is connected to two Internet Service Providers 315
`and 307. On the first provider 315, router-A 305 has an
`address of 5.0.0.2 and on Second Provider 307 router-A305
`has an address of 6.0.0.2. At site B 311, the address of
`router-B 309 interfacing with the First Provider is 5.0.0.3
`and 6.0.0.3 on the Second Provider. Thus, the addresses of
`5.0.0.2 and 5.0.0.3 belong to the first provider 315 and the
`address of 6.0.0.2 and 6.0.0.3 belong to the second provider
`20 307.
`Assume that router-A and router-B determine that they
`want to use the first provider for the communication using
`the control connection. In an embodiment using
`encapsulation, each packet which is addressed from 9.0.0.1
`to 10.0.0.2 is encapsulated into a larger packet by router-A
`at site A The creation of the data connection is implicit in
`this case. The source address of this packet consists of
`5.0.0.2 and the destination address consists of 5.0.0.3. The
`packet is forwarded to router-Bat site B. Router-B extracts
`30 the original packet from the larger packet, and forwards it to
`the eventual destination 10.0.0.2. A similar process is used
`for the reverse path of communication from 10.0.0.2 to
`9.0.0.1.
`In an embodiment employing network address translation,
`a slightly different process is generally used. In addition to
`the interface addresses, each router also obtains a block of
`IP addresses from each service provider. This block of
`address is referred to as the address space of the provider
`40 that can be used by the router. For instance, the first service
`provider assigns a block of addresses 5.0.0.10 through
`5.0.0.20 for site A, and another block of addresses 5.0.0.30
`through 5.0.0.40 for site B. The addresses of 5.0.0.10
`through 5.0.0.30 are in the address space of the first provider.
`45 Another block of addresses 6.0.0.10 through 6.0.0.30 is
`obtained from the address space of the second provider.
`In this case, a data connection is explicitly created for
`communication in step 211 of FIG. 2(a). The data connec(cid:173)
`tion establishment negotiates that address 5.0.0.10 be used at
`50 site A and address 5.0.0.30 be used at site B for communi-
`cation between communicators 301 and 313, 9.0.0.1 and
`10.0.0.2. Router-A at site A contains a mapping from source
`address 9.0.0.1 to 5.0.0.10, and a mapping from forward
`destination address 10.0.0.2 to 5.0.0.20. During data
`forwarding, router-A changes the source address of all
`packets from communicator 301 9.0.0.1 to communicator
`313 10.0.0.2 to 5.0.0.10, and changes the destination address
`of the same packet to 5.0.0.20. Router-B at site B, on
`receiving the packet, restores the original source and desti(cid:173)
`nation addresses of the packet. An analogous translation is
`done for packets on the reverse data path. The mapping of
`addresses are communicated to the router at the called site
`via the control channel established between the routers at the
`two sites.
`FIG. 4 illustrates an example block diagram of a router
`that is capable of service provider selection. Such a router
`401 includes an originating site interface module 403, a
`
`5
`
`65
`
`Cisco Systems, Inc.
`Exhibit 1006
`Page 7 of 10
`
`

`

`US 6,243,754 Bl
`
`5
`provider selector module 405, a called site interface module
`407, and a data forwarding module 409. The originating site
`interface module 403 is responsible for establishing new
`control connections to other called sites. The called site
`interface module 407 is responsible for receiving connection
`requests from other sites. The service provider module 405
`selects a specific service provider and is accessed by the
`called site interface module 407 and the originating site
`interface module 403 during their operation. The data for(cid:173)
`warding module 409 is responsible for doing data encapsu(cid:173)
`lation or address translation for the purpose of packet
`forwarding. This module operates on the basis of the con(cid:173)
`figuration determined by module 407 and module 403.
`In alternate embodiments the data forwarding module 409
`includes a translator module or an encapsulator module. The
`translator module is used when network address translation
`is used. The encapsulator module is used when packet
`encapsulation is used for data forwarding. In some
`implementations, the data forwarding module may consist of
`a translator module as well as an encapsulator module, with
`different modules being used for different sets of data
`connections.
`Thus an aspect of the present invention is to provide a
`method for an originating site to select a specific provider
`from a plurality of providers, for a set of application data for 25
`a called site. The method includes of the following steps:
`1. An originating site establishes a control channel to a
`called site. Using the control channel, the two sites com(cid:173)
`municate setup parameters for the exchange of a set of
`application data.
`2. The originating site selects a specific provider to handle
`this exchange of application data.
`3. The originating site communicates the selection of the
`specific provider to the called site using the control channel.
`4. The originating site establishes a connection to the 35
`called site using the selected specific provider.
`5. The originating sites routes all forward application data
`on the established connection.
`6. The called site routes all return application data trans(cid:173)
`mission on the same connection.
`In order to route the application data on a specific
`connection, one of the following two methods can be used:
`(A) The originating site maps the destination address for
`all data packets for the specific application data into a 45
`previously selected specific destination address. One map(cid:173)
`ping of this nature is to encapsulate an original packet into
`a larger packet which is sent to a destination address at the
`called site. The destination address must belong to the
`address space of the selected service provider.
`(B) The originating site negotiates the mapping to be used
`with the called site. A proposed mapping of the destination
`addresses for forward data communication and a reverse
`destination mapping for return application data is exchanged
`using the control channel. The reverse destination address 55
`and the forward destination address belong to the address
`space of the selected service provider.
`When the originating site has to exchange application data
`with another called site, the steps outlined above are
`repeated. The originating site establishes a second control 60
`channel between the originating site and the second called
`site, selects another provider for exchange of the application
`data, communicates the selection of the provider via the
`control channel, makes another connection to the new called
`site, and routes all data in the forward path on this estab- 65
`lished connection, while the called site uses this same
`connection for the return data transmission.
`
`6
`In some embodiments of the method the first called site
`and the second called site are at a common location, and/or
`the first provider and the second provider are common.
`Another aspect of the present invention is to provide a
`5 system enabling an originating site to select a specific
`provider from a plurality of providers, for exchanging at
`least one set of application data with a first called site. The
`system includes an originating site interface module to
`establish a control channel between the originating site and
`10 the called site for communicating setup parameters for a set
`of application data, a provider selector module to select the
`specific provider to handle all transmissions of the set of
`application data, an interface module to communicate with
`the called site on the control channel, such communication
`comprising a selection of the specific provider for a con-
`15 nection for transmitting the set of application data. The
`originating site router makes a connection to the called site
`using the specific provider, and routes all forward data of the
`set of application data to the called site via the connection.
`The called site router routes all return data transmissions of
`20 the set of application data to the originating site on the same
`connection.
`In an embodiment the system also include a translator
`module which may be of one of the following two types:
`(A) a translator that translate an arbitrary forward desti(cid:173)
`nation address for the connection into a specific desti(cid:173)
`nation address using a particular mapping, wherein the
`specific destination address belongs to an address space
`of the specific provider,
`(B) an original site translator that employs the interface
`module to negotiate a particular mapping with the
`called site via the control channel for a connection, and
`the called site translator that uses the particular map(cid:173)
`ping to map a reverse destination address for sending
`the return application data on the connection to the
`originating site, where the reverse and forward desti(cid:173)
`nation address are in the address space of specific
`provider.
`When a second set of application data needs to be
`exchanged with a second called site, the called site interface
`40 module establishes a second control channel between the
`originating site and a second called site for communicating
`setup parameters for a second set of application data. The
`provider selector module selects a second provider to handle
`all transmissions of the second set of application data,
`communicates to the second called site via the second
`control channel the selection of the provider. The original
`site interface module establishes a second connection to the
`second called site, and the translator module routes all data
`of the second set of application on the second connection.
`Still another aspect of the present invention is to provide
`an article of manufacture which includes a computer usable
`medium having computer readable program code means
`embodied therein for causing an originating site to select a
`specific provider from a plurality of providers, for exchang(cid:173)
`ing at least one set of application data with a first called site.
`The computer readable program code means in the article of
`manufacture comprises computer readable program code
`means for causing a computer to execute the steps outlined
`in this invention, or to create and/or configure a system that
`embodies the invention described here.
`Still another aspect of the present invention is to provide
`a program storage device readable by machine, tangibly
`embodying a program of instructions executable by the
`machine to perform the method steps for an originating site
`to select a specific provider from a plurality of providers, for
`exchanging at least one set of application data with a first
`called site.
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`30
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`50
`
`Cisco Systems, Inc.
`Exhibit 1006
`Page 8 of 10
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`US 6,243,754 Bl
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`8
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`10
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`It is noted that this invention may be used for many
`applications. Thus, although the description is made for
`particular arrangements and applications, the intent and
`concept of the invention is suitable and applicable to other
`arrangements and applications. It will be clear to those
`skilled in the art that other modifications to the disclosed
`embodiments can be effected without departing from the
`spirit and scope of the invention.
`Having thus described our invention, what is claimed as
`new and desired to secure by Letters Patent is as follows:
`1. A method for an originating site to select a specific
`provider from a plurality of providers, for exchanging at
`least one set of application data with a first called site, the
`method comprising:
`the originating site
`establishing a first control channel between the origi(cid:173)
`nating site and the first called site for communicating
`setup parameters for a first set of application data,
`selecting the specific provider to handle all transmis(cid:173)
`sions of the first set of application data,
`communicating to the first called site via the first
`control channel a first selection of the specific pro(cid:173)
`vider for a first connection used for transmitting the
`first set of application data;
`making the first connection to the first called site using
`the specific provider, and routing all forward data of
`the first set of application data to the first called site
`on the first connection; and
`the first called site
`sending all return data transmissions of the first set of
`application data to the originating site via the first
`connection.
`2. A method as recited in claim 1, further comprising the
`originating site using a particular mapping to translate an
`arbitrary forward destination address for the first connection
`into a specific destination address for the first connection,
`wherein the specific destination address belongs to a first
`address space of the specific provider.
`3. A method as recited in claim 2, further comprising:
`the originating site
`forwarding the particular mapping to the first called site
`via the control channel, and
`the first called site
`using the particular mapping to form a mapping of a 45
`reverse destination address for sending the return
`application data via the first connection to the origi(cid:173)
`nating site, the reverse destination address being in
`the address space of specific provider.
`4. A method as recited in claim 1, further comprising:
`the originating site
`establishing a second control channel between the
`originating site and a second called site for commu(cid:173)
`nicating setup parameters for a second set of appli(cid:173)
`cation data,
`selecting a second provider to handle all transmissions
`of the second set of application data, and
`communicating to the second called site via the second
`control channel a second selection of the second
`provider for a second connection for the second set
`of application data;
`the originating site
`making the second connection to the second called site
`using the second provider, and
`routing all forward data of the second set of application
`data to the second called site via the second connec-
`tion; and
`
`the second called site
`sending all return data of the second set of application
`data to the originating site via the second connection.
`5. A method as recited in claim 4, further comprising the
`5 originating site using a second mapping to translate a second
`arbitrary forward destination address for the second
`connection, into a second destination address for the second
`connection, wherein the second destination address belongs
`to an address space of the second provider.
`6. A method as recited in claim 5, further comprising:
`the originating site
`forwarding the second mapping to the second called
`site via the second control channel; and
`the second called site
`using the second mapping to form the second mapping
`of a reverse destination address for sending the
`return application data via the second connection to
`the originating site, the reverse destination address
`being in the address space of the second provider.
`7. A method as recited in claim 5, wherein the first called
`site and the second called site are at a common location.
`8. A method as recited in claim 5, wherein the first
`provider and the second provider are common.
`9. A method as recited in claim 5, wherein the first
`Provider and the second provider are a same provider.
`10. A method as recited in claim 1, further comprising the
`first called site confirming to the originating site via the
`control channel of receiving the first selection.
`11. A method as recited in claim 4, further comprising the
`second called site confirming to the originating site via the
`second control channel of receiving the second selection.
`12. A system enabling an originating site to select a
`specific provider from a plurality of providers, for exchang(cid:173)
`ing at least one set of application data with a first called site,
`35 the system compr