PAGE 75SEPTEMBER 1 0. 1990-------------------------------,.;,...------------------------------4

OWDALD

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Here is ODe way to get more informa­tion about OSI and GOSIP. TheGOSIP Usn"s Guitk is an cay-to­read introduction to OSI and GOSIPdesianed for federal employees whowill have to comply with the reauJa­tions. It can be obtained from:

sent. In addition, TP4 (similar to thetransport control protocol in the TCPliPworld), ensures that two programs on twodifferent computers can exchangestream ofdata.

F'mally, GOSIP specifies protocols to

tion. As long the packet is in an OSI­compliant format, the destination nodewill be able to read it.

One ofthe key components of the OSIstandards is a common addressing for­mat. Eventually, ifthe OSI visionaries gettheir way, every computer in the worldwill be reachable using the OSI networklayer. By setting up a standard addressingformat, we can ensure that all addressesare unique. For the federal government,the National Institute of Standards andTechnology, the developer ofGOSIP, willalso handle address administration.

While an add specifies a uniquelocation, the network also needs a way todetermine how to route a packet of.datato that address. In the current version ofthe· OSI documentation, each router(known as an intermediate system) mustbe told the location of reachable add~es. This i known as static routing.

The network layer delivers packets ofinformation from one computer to othersthrough an internetwork. The service ofthe network layer is a best~ffort delivery:Packets can aet lost, duplicated, ormangled in the network.

Within the transport layer, TransportProtocol 4 (TP4) pwantees that allpackets between two users are deliverederror free in the order in which they are

A kind ofnetworking esperanto, GOSIP was mandated by thegovernment, but adoption will be gradual.

technoloaies to be used. (See F'1I\lfe 1:Protocol stack.) Token ring, token bus,and CSMA/CD (known Ethernet) areall standards that were developed by theIEEE and ubsequently adopted by theInternational Standardization Organiza­tion.

All three technologies use an interfaceknown as the Logical Link Control.

For wide-area communication,GOSIP adopts ~.2S, such as Tymnet andTelenet, or the national networks offeredin Europe.

To comply with GOSIP at the subnet­work level, a vendor must offer one ofthese four ubnetwork technologies: to­ken ring, token bus, CSMA/CD, or X.2S.Note that there is no requirement to offerall the technologies.

PIOTOCIM. ITA Built on top of theubnetwork technologies i the OSI proto­

col c. The network, transport, .on,and presentation layer all add value to thelower layers. The combination ofservicesis then used by network application uchas the messaaing service.

The network layer combin differentubnetworking technologies together into

a coherent internetwork. A packet ofdatamay be forwarded over several differentsubnetworks until it reaches its destina-

ugust IS was the magic date forgovernment procurement special­ists: All future computer systemsmust be compatible with the new

Government OSI Profile (GOSIP). Thegoal is to ensure that all governmentsy tem meet certain basic levels ofinteroperability nd con istency. Will then w procurement standard bring instantcommunication ea ? Will it repl ce thecurrent TCP/IP . tnnd rds?

lIardly. xpcrt predict that it willtake as long as a d de of transitionbefore OSI becomes so integrated incorporations and government agenciesthat it truly repl ces the currently perva-ive T P/IP.

GO IP i sed on th Open Sy temInterconnect (OSI) standard d v lopedby the International Standards Organiza­tion. 0 I tand rd are hi hly pecificd um nt. that d tnil how v'rythingfrom I.A ~ tn . urity to n'tworkman g m nt will work.

o I con i t of ven lay rs of trans­port protocols - which. wh n adopted.h uld allo difli rent c mputers t hare

d ta and mg. While many r rchfacilities and government agencies cur­rently u TCP/IP protocol , many ex­pect OSI to catch on becau it willsupport more urson a network.

GOSIP takes a core subset of OSI,enough to make a minimal network, andmandates them as a federal standard. Be­cau GOSIP wa cl ified as a FederalInformation Proce ing Standard in Au-u t. new computer network and ignifi­

cant upgrad to existing networks mustinclud GO IP upport - or show goodcause.

A single networking technology haspotential for a host of benefits. Look atT P/IP for example. The governmentha. for many years required thatT P/IP be used in som governmentpurchases of computers, particularlythose for the military. The result is inter­operability: Computers that share the

me networking technology can shareinformation.

Government standardization on aingle technology also affects corporate

buyers. When the functionality is estab­Ii hed by tandard, vendors begin com­petin on price. Because the governmenti such a large purchaser, vendors areeager to enter the marketplace. Commer­cial users can ride on the government'spurchasing power to network their owny terns.

AT' ." OSI specifies ven levelof communications protocols. GOSIP,Version J specifies three levels of interop­erability among computing ystems:

• The subn twork (which con ists ofthe data link layer plus the phy ical linkla r). .

• The network.• The application.An e ample of a subnetwork i an

'Ethernet or token ring local area network.So why not just u the term LA ? In theOSI world we can expect to largenumbers ofwide-area connection.

A subnetwork is any technology thatallo two nodes connected to it toexchange information. Ethernet is aimple example: Any computer connect­

ed to the coaxial (or twisted pair) cablecan broad t data to any other node onthat cable.

GOSIP allows three types of LAN

PAGE7B SEPTEMBER 10, 1990

De of the bil elements missina'from GOSIP' a specificationfor dynamic routing, which al­lows an internetwortc router to

inform other routers about the pres­ence ofnew networks or new systemon networks.

Because dynamic routinl does notrequire manual intervention ­which static routinl does - it ismuch more respOnsive to cbanaes inthe topology of the networlc. If thereare multiple paths between two com­puters, a dynamic routina alaorithmwill decide which path i best. It willalso switch over to 1 d'rablepaths in the case ofa networtc outaae.

Another name for adynamic rout­ina alpithm is an IS-IS protocol,tbro~which routina information iselcbanaed between intermediate sys­tems. End system simply band ofTtheir packet to the nearest router. Therouter needs to know bow to fmd thedestination node, usina either dy­namic or static routina tables.

The reason that GOSIP doesn't in­clude dynamic routina . .mple: TheOSI committees have yet to decide ona dynamic routina allorithm. DiaitalEquipment Corp. bas proposed analgorithm that it in its soon-to­bc-released Phase V. known DEC­Net/OSI. The technical committeesare wortcina furiously to tum theDEC proposal into draft standardacceptable to other vendo but evenifeverybody IIfeCS with DEC, it willstill take 1001 time before OSI basan accepted international standard intbisarea.

Lack of dynamic routina is noproblem for simple networks of justane type ofsystem. But in a complextopology the . . crucial. UntilOSI and GOSIP can deal with the. TCP/IP will still hold the edaefor the larae complex networks.

COIn..... A popular miscon­ception about the GOSIP standard is thatit applies to all computers. In fact. GOSIPstandards apply to the communicationbetween groups of computers: internet­worldng.

To be GOSIP compliant, a vendorimply needs to support a single point of

however. GOSIP will be updated every 18months or so to add new requirementsand capabilities. Version 2 is already inthe works, and will include thinp uchthe X.SOO directory. rvice and the OSIVirtu I Terminal protocol .

"VeBion I la~ the 00. i foundation.Version 2 will expand on that 'cfoundation:' id Jerry Mulvenna of theN tion lin titute ofStandards and Tech­nology [NIST] and one of the authors ofGOSIP. "The GOSIP Advanced Require­ments Group determines what the 10v­ernment's needs are. NIST then monitORwhat products vendors have available. IftechnolOlY becomes available, GOSIPmandat th t agencies use 0 I tandardswhen they meet their needs. tt

The moving target aspect of GOSIP iskey: It y that NI T will takc an activerole in , I ·ting international ,tundardnd requirin that th y he u~ in

government procur men . NeedI tosay. th re will be computing environ­ments where this doesn't make sense. A'need for specific technologies and cost­savinp goals may serve as just cause fornot buying GOSIP-compliant products.

UIII..II-.I1IA'II Y. Basic GOSIP isreally just two services: fl1e transfer andmeaaging The services are provided onfour difTerent subnetworks: X.2S. tokenrinlt token bu and Ethernet.

That's not the end of the tory.

Rather than specifyinl all of theFTAM capabiliti GOSIP only requires

limited su •To be GOSIP compliant,a vendor need only provide a simplebulk-t n fer capability. Option I capa-biliti include to file attribut( uch IeCUrity or accountinl inform -tion bout the file) or to pieces offil (in the cue of rehinl an indexed file bya value).

•• ••• .. •• ,. e" 1('.

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no useful services for the user. GOSIP ini­tially sPecifies two services to be pr0­vided: X.400 bandlinl and thefile Transfer, Access. net M n ment(FTAM) service for to cia •

X.400 i a widely cceptedfor electronic m il net other mc..~handlinl . By 'n X.400, thelovernment hopes to be ble to exchanae

monl alilovernment ncies,well as to commercial providen.FTAM is a fairly IOJ)bisticated proto­

col for access to remote flies. "FTAM is ahuge, complex specification. It lives youa hernia to carry the documents around,tt

id John McConnell of InterworkinInc., in Boulder, Colorado.

A U The protocoltack builds the foundation that allo

two program to communicate. At thipoint, the n twork i II inf! trueture and

Forest&TreesTW is new software that helps you run your defined. Result: Forest &Trees gives you up-to-the-minutebusiness better. Installed on your PC, It automaticaJty Information for smart, timely decisions. And at a fraction of the1) collects data from PCs. minis, and mainframes 1111111111111111 cost of an exeartive Information system. it can beon your network. 2) combines the data Into use- on every~s desk. Call George in ourful information. the'Vital ' I ns·you use to manage, department to find out how you can beand 3) monitors these vttaI •sounding monitoring vttaI In just hours. A big promthe alarm if an indicator exceeds . you've we're ready to prove. Phone 1~281-0053

be used at the ion. presentation, andapplication layers of the networtc. The

ion layer tarts ( the name impli )ion between two proaram . The pre­

. nt tion I yer i common form t forthe exch n e of d t between difTerent.~tem . The application layer pull thiall tether, 1I0wing proaram to forman iation with nother by implyiving the n me of the taraet proaram

(known as an Application Entity Title orAE-Title).

PAGE 77

PROCESSING

will lead to the v it bility of more. ndcheaper product., for overnment andbu in buye alike.

Most 0 rven believe th t it will takeat I t two nd m ny 10 years forGOSIP's effect to be felt. All users ndgovernment offici I however, do agreethat there will be an effect.

"GOSIP will have a ripple effect," saidMcConnell of Internetwooong. "I guesswe don't caU it trickle down now thatReapn is gone." 0

Carl Malamud Is a san Francisco writerwho specializes In network Issues. He Iscurrently working on a book on DEC­Net/OSI, to be published next year.

980 Channel Computing Inc 53 in St. Newmarket NH 03857

D A T AI N

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&<:COrdinl to Frank Dzubeck. p ident ofCommunication Network ArchitectAInc. "There' no need for 0 I on the(I ktop. OSI i fint nd foremost for theinternet, between LANs and between ys­tem,," Dzubcck ide

Will OOSIP chanae how people dobusin ? It will certainly chanae howlovemment bid requests look. Given thatit takes anywhere from 12 to 36 monthfor the government to select computingsystem it seems pretty certain that theGOSIP-compliant systems will start ap­pearln in government offices within afew years.

Over time, the increase an governmentpurch of GOSIP-compliant ystem

MOMENTSG REA T

hardw reo Already, me bu in havecommitted to 0 I a Ion -term, fund ­mental eomputin trateay.

"We're not pi nninlon havinl OSI uju t nother protocol." id Laurie Bride,m n er of network architecture andtandard t Boeing Computer Services.

"We have too many to m n now.We're planninl on OSI providing thecommon networking capability that weneed. It doesn't preclude vendon provid­ing value-added, provided they add it inthe rilht place and not interfere with theinteroperability that the standards offer."

For the d ktop u r, however, theimportant protocols are applications uch

X Window, Postscript, and SQL,

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business better. Installed on your PC, It automatically Information for smart, timely decisions. And at a fraction of the1) collects data from PCs, minis, and mainframes cost of an executive information system. It can beon your network, 2) combines the data into use- on every manager's desk. Call David in our salesful information. the'VItal signs·you use to manage, department to find out how you can be monitoringand 3) monitors these vital signs, sounding vital signs in just hours. A big promise we're readythe alarm if an indicator exceeds values you've to prove. Phone 1~289-0053

ACT C IAL Over thelong haul GOSIP may encourage ven­dors to de elop cheap, interoperable

SEPTEMBER 1 0, 1 990

IP ACCEPT Many consultants andu rs are quite skeptical about OSIreplacing their current networks.

uGOSIP may be in the same basket asADA," id David Snellen president ofData Management Systems in Washing­ton. which provides technical support toagencie such as the Joint Chiefs of Staff."We have to have ADA, but we still dothings the normal way. We have standardequipment here, like Sun, DEC, Sequent,and VA clusters.' GOSIP doesn't addany functionality to what we already havewith TCPliP and DEC- et."

The problem with GOSIP is that manykey pieces such dynamic routing, aretill mi ing. (See sidebar, Page 76.)

"The first GOSIP kicking in in Augustdoe n't mean that OSI is here," saysInternetwooong's McConnell. "There's awhole lot of mi ing pieces. A heteroge­neous environment is the only placewhere OSI will have any advantage over aproprietary environment."

Still, govemment planners believeGOSIP lays the infrastructure that will al­low for increased use of standards in thefuture. In this way, GOSIP will offer agradual tran ition to OSI protocols.

int rconncl'tion. For e :lmple. v ndornn continuc to. II ('Oml)ute~ hn. I on

th proprictary Arcn t . uhn twork andu. in . m prtlprietnry n twork ~uch n

ovell'. tw:u . To he IP compli-ant. the vendor could provide a gatew y- a . in I computer that tran hatesincomin FTAM request to a propriet ryfit pr tocol and incoming X.400 mes-

es to proprietary m ging format.Most vendors plan to keep their own

proprietary protocols, and add GOSIP asa second set. "OSI will become everya ency's second languag , maybe theirfirst," id Richard d Jardins, vice pres­id nt of Interop Inc. and one of the origi­n I 0 I architect. "Ju t like English ise eryhody' second langua e. maybethrir finlt."

omp ni with the big t inv t-m nt in proprietary protocol such asDigital Equipm nt orp. and IBM. havebeen quic to cmpha. i7.c that they willupport a I. DEC ha. evcn gone far as

to chan th nam of it product fromo - et to DE - et/OSI.

The name change doesn't mean thatDEC is abandoning its own protocols. Itonl means that two protocol stacks areoITered: 0 I for communication to theout ide world and DEC- et for internalcommunications. DEC paints this strate­gy as "value-added" or staying ahead ofthe standards process.

OSI is "not a second language," saidSteve Kelly, a DEC marketing manager.UA good analogy is with automobiles.E ery year you have standard option andvalue- dded option. What was valuedded becomes standard."

DEC believes its protocols work in anarea that the standards have not yet cov­ered. While this is true in some in tances,such as DEC's Distributed Name Server,DEC appears to be duplicating the inter­national tandards in others. For exam­ple. D is h vily dependent on DataAcc Protocols, instead of FTAM.

One ofthe purposes ofGOSIP is to en­courage 051 use in situations where stan­dards are available. "If you have a needfor a rvice for which there is an interna­tional standard, you should acquireimplementations based on that standard.not implementations that will continue tolock you into one vendor," said NlSTsMulvenna.