Network access to internet and stored multimedia services from a terminal supporting the h.320 protocol

2 1 84209 NETWORK ACCESS TO INTERNET AND STORED MULTIMEDIA SERVICES FROM A TERMINAL SUPPORTING THE H.320 PROTOCOL S T~rhnir~' Field This invention relates to a method and a system for accessing the Internet through a multimedia product that supports an H.320 protocol.

10 R~rk5Lroun~ of the Invention Providing both muitimedia (voice, video and data) communication products and serYices to customers is playing an i~ dsi"yly more important role for ~leco" " "unications cu" ".a,~i~s today.

The power of multimedia communications is evident from the expansion in 15 "videoco"r~l~"~,i"g", in which a user at a video~,u"~r~ ci"y station can communicate "face-to-face" in real time with someone at a distant other vid~oco"r~ ,i"9 station.

The introduction of desktop videocc,l,r~r~llcing equipment is making multimedia communications even more prevalent.

Generally, multimedia communications uses 20 equipment i"c~"~.~rdLt:d as part of a general purpose computer, or integrated systems specifically designed for the task.

For example, the Vistium~M Personal Video (PV) product, available from AT&T, is a PCbased ~le~ol ,' t:n~,i"g product that consists of circuit boards that plug into the expansion bus of a PC, which is used in conjunction with a 25 video camera and ,, ' ' ~s software. A des~ io" of the Vistium product line can be found in "Vistium Products Give Another Point of ' ~ 2 2184209 View", by Robert M.

Howe lll, AT&T Technology, Volume 9, Number 4, vVinter 1994, pp. 18-21.

The Vistium PV allows users to exchange audio, video, and data through their PCs with one another user by communicating over ISDN S phone lines or over switched 56 kbps phone lines.

An MS-Windows~M based le:lec~l,r~ nci"g r, ,~ uses a Vistium-equipped PC to make a phone call to another Vistium-equipped PC or to another collllJdlil,l~ device.

The two users can then engage in a video phone call with the camera input of one user appearing in a window on the PC lO of the other user.

In addition, data may be shared either by the exchange of f les on the two PCs or through the use of shared s running simultaneously on both PCs.

As noted, one endpoint of the connection can be a Vistium-equipped PC or any other device which can exchange i, If ul ",d~iùn over the ISDN or 56 kbps 15 switched telephone lines using a protocol that is u"de,:,luod by both endpoints.

The Vistium PV employs the H.32û protocol that has been adopted by the ll l' -l ldliol~dl Telecommunications Union (ITU) as an illll:llldliUndl standard forvi(lelJt~ corl~ ~n~i"g.

The H.320 standard is a family of l~leco"~ n:n~ii"g standards developed and " ,~ ;. ,ed by the 20 ITU which el~cu""~asses a variety of standards for audio cu",,u,~ ,~iùl~, video ~.OIll,ull:55iull, and telephone call set-up and control.

The H.320 standard provides for the division of i"ful " ,dlion into three distinct streams: video, audio, and data, where "data" herein is intended to mean digital i, ,furl,,dliul~ that is not meant to be displayed as real-time 25 video or audio, and includes i"rul"Idliul~ to be displayed as text and data that is used to control ,, ': " ~5 or convey status to them. A PC 2 1 84209 .

operating in dUUUlddl lI,t: with the H.320 standard is thus con~lldi"ed to communicate only with one or more similar devices operating under the same standard.

As is well known the Internet is a vast collection of computers 5 communicating over a packet network which allows illeulllldlioll to be lld,~:.ft:r,~d between machines across the world. A PC typically accesses the Intemet through a modem onto a user s POTS (plain old telephone service) phone line or through a high-speed local area network (LAN).

Connecting a PC to the LAN requires a card known as 10 a LAN adapter that plugs into the computer s expansion bus.

I~rurll~dliùll is ~xul,ange.l overthe Internet using a protocol known as TCP/IP (T~d~l~",;,~ion Control PlulucoVlll'~ t Protocol).

In orderto facilitate the easy use of the Internet a plUy,d"""i"g interface has been developed providing high-level functions for pe, rur" ,i"g functions such 15 as sending and receiving data to and from a remote machine on the Internet.

For PCs running Microsoff WindowsTM this interface is called WindowsSocketsorWinsock(see e.g. M.Hall WndowsSockets, Microsoft Corp. 199~).

The Winsock interface allows a ~ud,dliu~, between high-level network I, :l - )s and low-level hardware 20 i~ e~ ~ldliulls In the Windows p~ u~ I dl l ll l lil lg environment Winsock . is i",~ ",e"~d as a dynamic link library (DLL) which is a file that contains ~y~ tA'~le ~ u" ~uu~ ,e"t;, that can be accessed by other 'i ,s.

The DLL must be available to a computer s operating system (i.e. the operating system must be able to find the DLL on the 25 hard disk) at the time that an -.r~ ' ' .1 requests access; but the DLL is 2 t 84209 i"depc:lldt:"~ of the:,, ' ' ,~ in the sense that the DLL can be changed or updated without needing to modify the ,, ' ' ~5.

A user of a Vistium or H.320 cùll,! dlil-le-equipped PC which is designed to communicate over ISDN or switched 56 kbps lines, is 5 precluded from accessing the Internet and the i~rullll ' , services available thereon without additional hardware and software, in addition to requiring access to LAN or POTS lines necessary for Internet service.

In order for a Vistium-equipped PC, to have the capability of accessing the Internet, therefore, it must be add;liol, 'Iy equipped with either a 10 LAN card for access to a LAN, or with a modem for access to a POTS telephone line.

Both alternatives require the additional intemal PC hardware and software plus the external structural infrastructure necessary to support the co""~uliol~ to either a LAN or a POTS line.

As noted, this LAN or POTS co""e-,lion is in addition to the col),~e-,liui, to either the ISDN or 56 kbps lines necessary for H.320 multimedia communications.

Any of the available prior art allt:l l, ' ~cs for supporting access to the Internet from a PC equipped to operate under the H.320 standard are therefore expensive from both a cost ~ldlld,uuil ,l and from a space requirement ~ldlld, ~Uil ,l.

With respect to the latter, 20 free space for such additional hardware acuo"""oddliu"s is very limited on the newer small and compact PCs currently being offered in the computer Illdlh~t~JIdCe.

An object of the present invention is to provide Intemet access to those terminals supporting the H.320 protocol.

~ ~~Cysf the InYen~ion s 2 t 84209 In a~.,ulddl ~c~ with the present invention, access to the Internet is provided to temminals supporting the H.320 protocol, over the data stream defined by H 320 standard, through a gateway server that is dialed by a user desiring access to the Internet.

The gateway server, in 5 turn, is conneckd over a LAN to the Internet.

The gateway server provides the user of an H.320 terminal access to the Internet through either a direct TCP/IP or a proxy TCP/IP methodology.

In the direct TCP/IP I~ odoloyy, a function call from a user's H.320 terminal's:,, ' " ~ program is made to a custom Winsock DLL lo to directly format this out-going request according to the TCP/IP protocols used for the exchange of i"f~" " IdLioll over the Intemet.

The TCP/IP formatted request is then Lldll ,,llitL~:d over the H.320 data stream to the gateway server, which passes the data directly onto the Internet.

IllrulllldLi~ll retrieved overthe Internet is received bythe 15 gateway server in TCP/IP format, and then passed, in that format, to the user's terminal over the H.320 data stream.

The custom Winsock DLL within the terminal removes the TCP/IP formatting and passes the illrulllldLiOI~ to the ~ program, where it is available to the user.

In the proxy TCP/IP Ill~tllodolo~y, when the 1,), ' ' ~ program 20 makes a function call to the Winsock DLL, rather than fommatting the request to the TCP/IP fommat, a custom Winsock DLL passes the request to the gateway server over the H.320 data stream.

The gateway server, in turn, receives the request and then makes a ~.ull~olldi~lg function call through its own standard Winsock DLL, 25 which in turn is formatted to the TCP/IP format for output onto the Internet for delivery to an i"ru"" ' ~ service provider (ISP).

6 2t84~09 Illrulllldliull retrieved from the ISP over the Internet is received by the gateway server wherein the standard Winsock DLL removes the TCP/IP formatting and transmits the i"'~ r" ,d~ioll back to the user s H.320 terminal over the data stream.

The user s custom Winsock DLL then S collects this i~ ~ru~ dLioll and passes it to the .-r l .~ program where it is available to the user.

Brief Descr~ntion of the Drawin~s FIG. 1 is a block diagram of a simplified telecommunications 10 network in accu,dallc~ with an ~" ~L,odi",e"L of the present invention;

and FIG. 2 shows the software protocol stacks d'5V~;- '''d with both the H.320 user terminal and the gateway server necessary to effect the proxy TCP/IP l"~tl"~dolugy of the present invention and FIG. 3 shows the software protocol stacks a~c ~ with both the H.320 user terminal and the gateway server necessary to effect the direct TCP/IP ~ Ll lodolo~y of the present invention.

7 2 1 84209 r C~,! ~ . ~4ti~n vVith reference to FIG. 1, a simplified telecommunications.

network in acco,~dllue with the present invention is shown.

It should be yl ~ d that the network of FIG. 1 includes other elements, which S have been eliminated in order to simplify the figure and in that they are not necessary for an u"de,ala"di"g of the present invention disclosed herein.

The network shown includes plural muitimedia tenminals 101, 102, 103 and 104.

Of course, an actual network would include many more such terminals, which can communicate with each other in a multimedia fashion over separate audio, video and data streams.

Each multimedia tenminal may include a Vistium PV product available from AT&T, which is compliant with the H.320 protocol, or may be another H.320 compliant tenminal available from any other source such as Intel's ProShare temminal.

As shown illustratively for temminal 102, each terminal generally includes a p,uc~ssi"g unit 105, a CRT 106 and a camera 107. A multimedia terminal 102 may also include an ~.~so-; ' d telephone 103 located external to the ,ulOC~:SSi~ ,9 unit 105 for purposes of dialing another terminal's telephone number when the prucessi"g unit 105 is incapable of doing so directly.

The p~u~essi~y unit 105 may be a general purpose computer with multimedia capable equipment ill~,ul~Juldl~:d therein, such as the Vistium board set which allows a conventional PC to perform video and ISDN communications that are compliant with the H.320 protocol.

Alternatively, the ~, ucessil ,g unit may be a multimedia specif c device.

8 21 84209 The H.320 compliant multimedia terminals 101, 102, 103, and 104 are designed to communicate over ISDN or switched 56 kbps facilities.

Thus each communications link 111, 112, 113, and 114 which connects terminals 101, 102, 103, and 104, respectively, to the Public 5 Switched Telephone Network may be an ISDN Basic Rate Interface (BRI) phone line or switched 56 kbps line(s).

As related to the communications link over which an H.320 multimedia terminal communicates, the ISDN BRI phone line and the switched 56 kbps line(s) will be referred to herein in the alternative as the "bearer lO channel".

If the bearer channel is an ISDN BRI line, the channel consists of the conventional ISDN 2B+D channels in which the two B channels (where a B channel has a bandwidth of 64 kbps) are used for providing separate data, voice and video streams.

In a preferred i,,,,ul~,,,e,~tdliun, the video stream is at 64 kbps, the audio stream is at 15 16 kbps, and the data stream is at 32 kbps.

If the bearer channel is a switched 56 kbps facility, the preferred ,:",I,o.li",~"l would i"cor,uo, ' two 56 kbps lines, with the video, audio and video streams being divided into the three streams as defined above for the ISDN line.

The H.320 tenminal is also capable of operating over a single 56 kbps switched line 20 in which for maximum data L,dns,,,;,,iu,, capability, the video and voice streams can be minimized.

Furthenmore, in setting up a multimedia call over ISDN or switched 56 kbps facilities, the allocation of bandwidth can be allocated to the audio, video and data streams in a flexible manner.

Links 111, 112, 113, and 114 are connected to switches within 25 the Local Exchange Carriers (LECs) ~o. i..l~d with each terminal.

As shown in FIG. 1, terminal 101 is connected to LEC 115, both terminals 2 1 84209 .

102 and 103 are connected to a common LEC 116, and temminal 104 is connected to LEC 117.

Each LEC may include a 5ESS(I~ switch manufactured by AT&T Corp, or other switch. LECs 1 15, 116 and 117 are connected to a switch 122 within the l,,lc,,~ ,I,dl,~e Canrier (IXC) switched network 123 by means of paths 118, 119 and 120, respectively, that may be ISDN Primary Rate InterFace (PRI) lines consisting of 23B+D channels, T1 lines, switched 56 kbps lines, As~".,lll.")~us Transfer Mode (ATM) packet medium, or other digital s",;~iul1 facilities.

Switch 122 may be a 4ESSTM switch manufactured by AT&T Corp.

In normal multimedia communications any of the H.320 compliant terminals 101, 102, 103 and 104, can communicate with each other, ~ .l Id~)yil ,9 video, voice and data over the separate video, voice and data streams defined by the H.320 standard.

In a~,co,~dllce with the present invention, the H.320 terminals 101, 102, 103 and 104, in addition to having the ability to communicak with each other, are provided with the additional capability of accessing the Intemet 130 over their data stream by dialing, either through their ~c50. ~ ' telephone set or through their processor, a gateway server 125 that is connected to the Internet 130.

This gateway server 125, as shown in FIG. 1, is connected through its ~so..i,,l~cl LEC 126 to switch 122 within the IXC network 123.

Alternatively, however, server 125 may be directly d''SCi~ ' d with switch 122, being co-located with the switch 122 or located apart from the switch 122, but connected directly thereto, 2s bypassing the LEC 126.

As shown, the path 131 between switch 122 and LEC 126 and the path 132 between LEC 126 and gateway server IO 2 1 ~4209 125 may be PRI ISDN, switched 56 kbps, T1, ATM packet transport medium, or other digital facilities.

Gateway server 125, over path 132 or multiple other parallel paths, is capable of simultaneously serving a plurality of H.320 terminals.

An accessing user is connected through S gateway server 125 onto the Internet 130 over path 134, which in the preferred ~"IL,o-ii",erll would be a LAN Ethernet co~ e~lio~.

The Internet is connected to a plurality of Irlrulllldl;vl~ Service Providers (ISPs), shown illustratively as 135 and 136, which provide i,,ru,,,, " :) and/or services to accessing users.

As can be noted, ISPs 135 and 136 10 have ~50~ . d .l '~ ~5 137 and 138, respectively, which store "ru, 1 l Idlion and/or data which may be accessed by a user.

In order for a H.320 terminal to access the Internet over the data stream of its bearer channel, a user's request, or "function calln, or data to be Lldl~ d to a remote machine or ISP, must be converted into 15 the ~Id,~da,~ d TCP/IP fon nat used over the Internet Similarly, data from a remote machine or ISP must be converted from the TCP/IP format into a format usable by the H.320 terminal.

In acuo,vd"ce with the present invention, an H.320 terminal and the gateway server 125 can function together either in accol~d, l~ with either a proxy TCP/IP 20 Ill~lllodoloyy or a direct TCP/IP methodology, described below.

In the proxy ,,,~lllodùloyy the gateway server 125 acts as a proxy for Winsock calls made from the H.320 tenminal accessing the Internet.

Whenever an :3,, 'i~;dliull program (such as Mosaic, Netscape, or any other Internet , ,~ s program) resident on any of the H.320 25 terminals 101-104 makes a function call to the vVinsock DLL, the request contains the name of the function and any pdldll l.,~,ra passed Il 2 t 842~9 in the function call.

The gateway server 125 receives the request from the H.320 data stream and makes the co"~:",ol,di"y function call.

Since the gateway server 125 is connected to LAN 134, it uses a standard Winsock DLL to convert the call to TCP/IP format.

When the 5 standard Winsock call is completed and a response returned from the ISP to which the call is directed, the gateway server 125 sends a response back to the originating H.320 terminal 203 on the data stream of the bearer channel.

This response may have status illfull lldliul~ or data and when retumed to the originating terminal 203, completes the lO user's function call.

FIG. 2 shows the software protocol stacks 201 and 202 ~ol~.i..' d with an H.320 terminal 203 and a gateway server 204, respectively for the proxy methodology.

As shown, terminal 203 and server 204 are connected to each other via ISDN facilities 205 and server 204 is CO~ uL~cl to the Internet 200 by means of a LAN Ethernet 207.

As previously described, however, the H.320 protocol can also be supported over switched 56 kbps facilities.

The A!, ' " ~, Program module 210 in software protocol stack 201 is a standard program such as Mosaic or Netscape, which function 20 is to retrieve illrUllllaliurl from the Internet and display it to the user and to accept requests in the form of function calls from the user and pass them onto the Internet 206.

The Custom Winsock DLL module 211 provides a standard interface between the Al~ 5 Program module 210 and the data transport medium 205, which in this invention is the 25 data stream of the H.320 bearer channel.

In addition to sending illfUlllld~iull over the H.320 data stream, the Custom Winsock DLL 12 2 1 84209 module 211 perfomms the additional step of packaging requests in the form of function calls and any pdld~ t~l~ passed in the function call from the A!:, 'k,dlio,~s Program into a format for lldl lal lliaaiOI~ over the H.320 data stream to the gateway server 204.

In addition to managing 5 all i~rolllldlion distribution to and from the Al~ s Program module 210, Custom Winsock DLL module 211 attaches an identifier to each i"" " Idlio~ request that can be ~cso, ~ -.' with the requesting aFF' " 1. A Communications and H.320 Controller module 212 functions to pass these packaged requests onto the H.320 data stream lO of the bearer channel.

Module 212 functions without regard to the fact that a packaged Winsock request may be incorporated within such data.

Module 212 further functions to control the co",1e-,lion between terminal 203 and server 204, ensuring that the ISDN or 56 kbps phone line culllleu~ion is IlldillLdilled.

The User Interface module 213 performs the 15 function of ~ldL,lk,lli,lg the connection by dialing the number ~,o~ with gateway server 204 when the user of H.320 terminal 203 places a call to the gateway server to access the Internet.

Module 213 also fundions to monitor for signals from the phone, from the switch, and from gateway server 204, and to .li~cor" ,eul the conl1e~,~iul~ when the 20 user of terminal 203 ~ ,o~ e~,L~ the call.

All such signals are acted upon i,~depel1d~"Lly of the A,~r ~: - Ib Program module 210 and the custom Winsock DLL module 211.

If terminal 203 is a Vistium terminal, then a Vistium Software Development Kit (SDK) module 214, a software product avai~able and sold by AT&T Corp. in cu, " ,e-,l;ol1 with its Vistium 25 PV product, provides the lowest level fulluLiull-' '~ for placing the packaged requests onto the H.320 data stream of bearer channel 205.

13 2 1 84209 If the H.320 terminal is other than an AT&T manufactured Vistium product, then an SDK ~ ,o,,i,-l~d with such other manufacturer's H.320 terminal will provide this functionality.

At gateway server 204, within software protocol stack 202, a Vistium SDK module 215 le~.ùylli~eS the data received on the H.320 data stream of bearer channel 205 and notifies Communications and H.320 Controller module 216 that data has been received.

Module 216 accepts this data and passes it along to the (~ ;'Proxy module 217. ~ ;'rroxy module 217 ~",pauhdgès this passed-along il ,ful Illd~iOIl, which is a Winsock function call and the pdldl 11~ ~.o.; ~--1 with the function call, and makes a Culle~polldill9 standard "real" Winsock function ca~l to its standard Vvinsock DLL module 218.

TCP/IP module 219 fommats this Winsock call for output to a LAN adapter card (not shown), which outputs the fommatted function call over Ethemet connection 207 onto the Internet 206.

Status i,,fu,,,,dLiun or data retrieved from the Internet in response to the function call is received by TCP/IP module 219 in gateway server 204, which alerts the standard Winsock DLL module 218, which removes the TCP/IP formatting and passes the ill~.llldliùl1 to the G-' ._J/rroxy module 217.

The C- ' .~ .~;'rroxy module 217 packages the i"' IlldliUI1 into a format lecoylli~dble by terminal 203 and passes the packaged illfulll, ' , to the Communications and H 320 Controller 216.

The i"" Illdliol~ is then passed down to the Vistium SDK module 215 and lldl)~,llilled on the H.320 data channel of the bearer channel z5 205 to terminal 203.

At temminal 203, the Communications and H.320 Controller module 212 converts this i,,ru,~,,aliùl1 into a fomm that can be 21 84~09 . ~ 14 It:coy"i~t:d by the Al), ' )s Program module 210 and then retums that i"ful " IdtiUI) to the A~ s Program for display or storage at tenminal 203.

In this embodiment of the present invention the Custom vVinsock 5 DLL module 211 that performs the '~ desu,i~d packaging and ~"",a- hdy;"g functions is readily illl,ult~ d by one skilled in the art.

Similarly the User Interface module 213 and the Communications and H.320 Controller module 212 in software protocol stack 201 at terminal 203 and the G ..~/FIu,~y Module 217 and Communications and H.320 Controller module 216 in software protocol stack 202 at server 204 are also readily il",ul~",e" ~ by one skilled in the art.

FIG. 3 shows the software protocol stacks 301 and 302 ZI~CO~ d with temminal 203 and gateway server 204 ,~pe~ ly for the direct TCP/IP i" ,pl~" ,~ dliUI) of the present invention.

Similar 15 numerical des;y"dliol-s given to the temminal server and ~o-; ~ d network elements in this figure are the same as are used in FIG. 2.

In this direct TCP/IP ~"lbodi,"e"t as in the proxy TCP/IP e"l~odi,"e"l described above theA! ' -,s Program module 310 in software protocol stack 301 ~so..;.-~ d with terminal 203 makes a function call to 20 a Custom Winsock module 311.

Instead of packaging the Vvinsock request to be serviced by a proxy however Custom Winsock module 311 passes a vvinsock request to TCP/IP Protocol Stack module 312 which directly converts the request into the TCP/IP format and then passes that formatted request to the Communications and H.320 2~ Controller module 313.

As in the previous 7",Lodi",e"l module 313 passes that data to the Vistium SDK for ~Idll~ siUII on the H.320 data 15 21 84209 stream of bearer channei 205.

At gateway server 204, Vistium SDK module 316 receives that data and passes it on to the Communications and H.320 Controller module 317, which alerts the Gateway module 318.

Gateway module 318 takes that data, already in TCP/IP format 5 and sends it the lowest part of a TCP/IP stack 318 for output to a LAN adapter card co""e~,Lt:d to Ethernet 207 and then onto the Internet 206.

Inasmuch as the request received by server 204 from terminal 203 is already in IP format, it should be noted that the software protocol stack 302 does not require a Winsock DLL.

In the opposite direction, data from the Internet is reoeived by gateway server 204 in TCP/IP format. TCP/IP module 318 picks up the data as is it comes off the LAN adapter and passes the data, still in TCP/IP format to the Gateway module 319.

Gateway module 319 passes this data to the Communications and H.320 Controller module 317, which sends it over the H.320 data stream of the bearer channel 205 for 1Icul::~llli55ioll to terminal 203.

At terminal 203, the Vistium SDK module 315 receives the data and alerts the Communications and H.320 Controller 313 which passes the data to the TCP/IP Protocol Stack module 312.

Module 312 interprets the data in TCP/IP fommat, unformats it, places in a format familiar to the I-r~ " ~5 programs, and passes it to Custom Winsock module 311.

Module 311 then returns the data to the A~ ' " ns Program module 310, from where it is stored or display to the user of terminal 203.

As in the previous embodiment, User Interface module 314 and Communications and H.320 Controller module 313 within terminal 203 are used to establish a call, and to monitor the phone line for signals ~ 16 21 84209 from the phone from the switch and from the gateway server.

The Communications and H.320 Controller module within server 204 perform a co", "el,td,y function As in the previous e"~l,odi",e"~ the custom soflware modules are readily i" ,~ " ,e"~t:d by one skilled in the S art.

With reference again to FIG. 2 as previously noted the H.320 protocol supports a flexible allocation of bandwidth to the data voice and video bit streams.

Thus in order to increase the throughput of the data retrieved from the Internet 130 by gateway server 125 and 0 1l dl l::>rt~ d over the data stream of the bearer channel to a requesting terminal, the bandwidth allocated to the data bit stream can be increased larger than its usual 32 kbps.

Thus by su~ldl ,t;.. ly reducing the ~dl ~ allocated to the audio and video streams, the bandwidth of the data bit stream can be increased to approach the entire 15 bandwidth of the bearer channel.

Throughput can also be increased by employing c~",~ siull and decu" ,~,~ss;on of the data stream.

Thus a l u"",,~ssu,/~ec~",~ sor 145 shown ?e9: with tenminal 1û1 and a co,,,~,,tsssol/.lecur,,~ sor 145 ?C9 with gateway server 125 together serve to compress data to be 1, dl 1511 lit~d over the H.320 20 data stream of the bearer channel from one end and then de~ u" ,~ ,s such c~",~ ssed data at the other end of the bearer channel.

The effective data transfer rate can thus be Sl.lb~ldl l';...ly increased over the nominal 32 kbps bandwidth of the H.320 data stream.

Cu",,~"~aso,/deco",,~,~,sor 146 can be s~ l,dLI~ connected to line 25 132 for use only when a termlnal using COI~l,ul~C,aiOll and decu",~ asiol~ accesses gateway server 125.

17 2 ~ 84209 The above-described ~ boui~ a are illustrative of the principles of the present invention.

Other e, ,IL,o,!i,,,e, ,ts could be devised by those skilled in the art without departing from the spirit and scope of the present invention.