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x. EVALUATION OF OPTIONS We present a summary of the strengths and weaknesses of each option, followed by a detailed evaluation for each set of criteria. SUMMARY Option l's primary benefit is that it would allow the DOD to obtain the benefits of standard commercial products in the communication protocol area at an early date. These benefits include smaller development, pro- curement, and support costs; more timely updates; and a wider product availability. By immediately committing to TP-4 as a costandard for new systems, Option ~ minimizes the number of systems that have to be con- verted eventually from TOP. The ability to manage the transition is better than with Option 2 since the number of systems changed would be smaller and the time duration of mixed TOP and TP-4, operation would be shorter. Interoperability with external systems (NATO, government, and commercial), which presumably will use TP-4, would also be brought about more quickly. Option ~ involves greater risk, however, since it commits to a new approach without a demonstration of its viability. As with Option i, a primary benefit of following Option 2 would be obtaining the use of standard commercial products. Unit procurement costs probably would be lower than with Option ~ since the commercial market for TP-4 will have expanded somewhat by the time DOD would begin to buy TP-4 products. Risk is smaller compared to Option ~ since testing and demon- stration of the suitability for military use will have preceded the com- mitment to the 150 protocols. Transition and support costs would be higher than for Option 1, however, because more networks and systems would already have been implemented with TOP. Also this is perhaps the most difficult option to manage since the largest number of system conver- sions and the longest interval of mixed TOP and TP-4 operations would occur. In addition, interoperability w i th external networks through stan- dardization would be delayed. The principal benefit of exercising Option 3 would be the elimination of transition cost and the risk of faulty system behavior and/or delay. It would al low the most rapid achievement of ful ~ internal interoperabi l- i ty among DOD systems . Iran ageab i ~ i ty shou ~ ~ be good, s i no e on l y on e set of protocols would be in use (one with which the DOD already has much experience) and the DOD would be in complete control of system evolution. Procurement costs for TOP systems would remain high compared to standard ISO protocol products, however, and availability of implementations for -53 -

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new systems and releases would remain limited. External interoperability with non-DOD systems would be limited and inefficient. In summary, Option ~ provides the most rapid path toward the use of commercial products and interoperability with external systems. Option 2 reduces the risk but involves somewhat greater delay and expense. Option 3 provides a quicker route to interoperability within the Defense Depart- ment and at the least risk, but at a higher life-cycle cost and incompati- bility with NATO and other external systems. DEFENSE DEPARTMENT OBJECTIVES VERSUS OPTIONS The committee has identified a set of DOD objectives for transport protocols, discussed in Section IT of this report. In this section we discuss the potential of each of the three options for achieving those objectives. The objectives have been grouped into five major categories that serve as criteria for evaluation of options. Functional-and-Performance Objectives There are certain functional and performance objectives that standard DOD transport protocols must satisfy. Key objectives include security capabilities, the ability to establish message precedence in crisis SitU- ations, and survivability of continuing operations when failures occur and portions of the network become inoperable. This implies continuous avail- ability of the primary data transmission network and the ability to recon- figure the networks to operate after some of its nodes are lost. As previously stated, the two protocols are functionally equivalent. TCP and TP-4 have equivalent reliability characteristics and are able to detect and recover from failures. The committee also concludes that robustness, availability, and performance in crises are equivalent using either protocol. The committee concludes that all three options equally satisfy the functional objectives that DOD requires. Since the performance characteristics of TCP versus TP-4 will be a function primarily of the particular implementations, the committee con- cludes that the two protocols are sufficiently alike that there are no significant differences in performance of a TCP or a TP-4 implementation of equal quality when each is optimized for a given environment. If Option ~ is selected, early implementations may result in subopti- mal performance. Option 2 specifies that there be a demonstration net- work established that will provide time for adjustment, testing, and gaining experience. Option 3 would result in no reduction in performance of current networks. The maturity of TCP has resu1 ted in many implementa- tions that have demonstrated good performance. This experience provides a knowledge base for future implementations of either TCP or TP-4. In either case, however, initial implementations of TCP or TP-4 may be SUb- optimal and require additional development to optimize performance. -54-

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Maximizing Interoperability A high-priority DOD objective is interoperability among its internal networks and among internal networks and non-DOD, external networks, in- cluding NATO. Interoperability allows users of a network to haste access to applications on the same or other networks. Option 3 would allow the DOD to increase internal interoperability most rapidly by continuing to mandate use of TOP for all new systems. Interoperability with external systems, however, the vast majority of which are expected to use ISO standard protocols, will remain limited. The more quickly DOD moves to use TP-4, the more rapidly external interoperability will improve. In the short run internal interoperabil- ity will be reduced due to the existence of both TOP and TP-4 protocols by different subsets. This problem is greater With Option 2 then Option ~ since the number of systems and the length of time both protocols are in use is greater. In both options the problem can be reduced by provid- ing special servers and translating gateways to provide limited interoper- ability where needed among subnets using different protocols. Minimizinq-Procurement, Development, and Support Costs A DOD goal is to assure availability of commercial-grade transport systems from vendors and minimize development, procurement, and continuing support costs. Both Option ~ and, after demonstration, Option 2 result in DOD adopting the TP-4 standard that has the endorsement of both national (ANSI) and international (ISO) standards organizations. Further, this protocol has been endorsed for use by NATO, the European Computer Manufac- turer's Association, the Computer and Business Equipment Manufacturer's Association (CBEMA), and the NBS Institute of Computer Sciences and Tech- nology for the information processing community of the federal government. The result of the endorsements will be widespread use of the standard protocol in worldwide networks and a large number of vendors supplying commercial grade products supporting TP-4. As previously noted, many vendors have already stated they plan to develop TP-4-based products and many are already doing this in-house. Thus a large market and large ven- dor base will assure the availability of commercial grade TP-4 products. A large market and supply of commercial-grade products will give DOD a large competitive base from which to select its data transmission sys- tems. The effect will be to reduce DOD acquisition cost because large markets allow vendors to amortize development and support cost over a large base. This favors adoption of either of the options that results in DOD using TP-4 as its standard. With the availability of commercial-grade products, vendors will take the responsibility for continuing maintenance and enhancements of the product. Transmission products are tightly coupled to the operating sys- tems on the host computer systems in which they operate. With vendor support of the products, evolution of both the host computer operating -55-

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system and transmission system will occur in synchronization. This again favors the adoption by DOD of either the Option ~ or Option 2 that results in TP-4. In these options much of the support cost is covered by the ven- dors and spread over the large market base. This reduces the development and maintenance cost passed on to the DOD. The committee does not believe that a large market beyond the DOD will develop for TCP because worldwide markets for products will be based on the ISO standards. Consequently, if the DOD chooses Option 3, only the DOD-dedicated vendors would supply TCP as standard products resulting in a smaller market and supply for TCP products and limited availability of TCP products. If DOD remains with TCP, many cornrnercial vendors will be forced to develop and support both the commercial standard products (TP-4) and DOD- standard special products (TCP) to stay in both markets. In many cases only the large market-based products such as TP-4 will be considered stan- dard and TCP products will be considered special products. The effect is higher development and support cost to the vendors which would be passed on to DOD. Thus the incentive for continuing enhancement to the special product, TCP, would be reduced. This responsibility would be passed to DOD, also resulting in higher costs. Ease of Transition The DOD is concerned with the ease and risk associated with transition from the current network architecture using TCP to its future network architecture. The objectives for DOD are to reduce the interruption of data communication services supplied by its active networks; minimize the risk of using an immature, untried protocol; and maximize the use of tne critical skills, knowledge, and experience of the engineers who develop the communications products. The maturity of TCP and the momentum that exists in the DOD community for implementing future systems using TCP would favor Option 3. Selection of Option 3 would minimize interruption of service and minimize risk. With this option there would be no transition; the DOD would remain with its current Policy. There would be no conversion costs and the only risks for DOD would be associated with poor implementations of new TCP-based products. The committee believes that much of the technical risk is associated with implementations. Therefore, given the relative state of their speci- fications and implementations as discussed earlier, the committee feels that the risks are comparable for implementing new products for either TCP or TP-4. Since DOD is acquiring many new networks the implementation risk of either TCP or TP-4 will be equal. If DOD chooses Option i, it will display confidence in the TP-4 speci- fications and in the vendor's implementations through its immediate com- mitment for TP-4 use in new military networks. DOD wild, in effect, be -55-

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making a commitment similar to that of vendors who are planning this pro- toco] for their standard products. Since most new networks would not use a transport protocol other than TP-4, this minimizes the number of net- works and therefore the cost of converting and maintaining TOP networks to TP-4. Since the standard TP-4 products from vendors are not available today, DOD endorsement of TP-4 may have the effect of accelerating vendor devel- opment of standard products. These products are expected to be generally available by 1986. Thus Option ~ can be consistent with the manufac- turers' expected product plans. Option ~ provides, therefore, the least conversion cost but with higher risk for DOD conversion. If DOD chooses Option 2, then the risk that TP-4 wild not meet DOD needs is reduced since there is no commitment to use this protocol until a successful demonstration is completed. In the interim, many networks will have been committed using TOP, resulting in nigher conversion costs than with Option l. In summary, Option 2 provides a lower risk approach for DOD to convert to TP-4, but will encounter the higher conversion cost. There is a great deal of experience with TCP and thus there is an engineering community that is highly knowledgeable about it. As previous- ly noted, however, if DOD remains with TCP, some DOD vendors will be forced to support multiple protocol products. The functional equivalence and similarities between TCP and TP-4 permit an easy transition for the experienced engineer to move from TCP to TP-4. Option 2 allows more time for this transition to occur, and thereby minimizes the risk associated with a complete switch to TP-4. In addition to the transport protocols, a transition from TCP to TP-4 also involves the conversion of applications. The committee has concluded that the services provided by TCP and TP-4 are comparable and applications software can be moved from TCP to TP-4 without loss of functionality. Ob- viously, Option 3 requires no conversion to existing applications on cur- rent implementations. Option 2 will result in more applications interfa- cing to TCP than Opt i on 1 , thu s potent i al ly i ncreasing conversion costs. In the future DOD could minimize the cost of conversion by standardizing the services provided by the transport layer to the applications. Manageability and Responsiveness to DOU Requirements The final set of objectives is concerned with the degree of difficulty that DOD will experience in managing its installed networks and future networks. As communications requirements evolve, DOD must have the ability to alter specifications so they will satisfy new requirements. Finally, DOD requires facilities for validation of protocol implementa- tions as they are added to their networks. Since Option 3 is to maintain the status quo, no additional management difficulty is anticipated. -57-

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Both Option 1 and Option 2 will cause some additional management dif- ficulties since they require that the current momentum for adopting TCP to be redirected toward TP-4 without loss of intensity. In addition to this change, DOD must manage both TCP and TP-4 networks. This will add to its management difficulties. Option 2 will result in greater management difficulties than Option ~ due to the larger number of TCP systems that must eventually be converted and the larger time period over which both protocols must be supported. There are benefits from each option. If Option 3 is selected, DOD and its vendors have sole responsibility for determining what changes are needed, implementing the change, validating the change and the ongoing maintenance of the standard. If either Option ~ or Option 2 is chosen, then DOD may encounter difficulty in persuading the standards groups to adopt its proposals; however, DOD would gain the experience and knowledge of the industry standards-making bodies. The industry standards bodies should be receptive to good technical arguments for correction of errors or apparent major deficiencies in the protocol. The standards bodies that maintain the standard should become a technical resource for DOD to develop its military specifications. Since TP-4 will be a commercial standard, those vendors who adhere to the standard will insure that validation facilities are in place. The National Bureau of Standards has a test facility for TP-4. No such faci- lity exists for TCP. If Option ~ or Option 2 is chosen, DOD can use this facility to validate vendor implementations. DOD should work with NBS to develop a similar facility for TCP. This is particularly important for new implementations of TCP. DOD should continue working with and through NBS in getting needed protocol revisions introduced into the appropriate standards bodies. In summary, Option 3 results in no new management difficulties while Option 2 causes the greatest difficulties. Option ~ allows DOD to move toward commercialized standard products with the smallest addition of management tasks. EFFECT OF PROPOSED OPTIONS ON MARKET SHARE Option ~ would quickly reduce the market held by TCP products as TP-4 products begin to take hold in the marketplace. In addition, it would en- hance the ability of U.S. manufacturers to compete in the world networks market based on ISO standards because they would not have to engage in parallel development nor support two sets of protocols for very long. Option 2 could have a comparable but less pronounced effect in the market- place and it would be delayed. Because of the very probable rapid deploy- ment of TCP-based systems in DOD networks while the TP-4 is still in the demonstration phase, however, many more networks than in Option ~ would probably end up using TCP. This would tend to reduce the U.S. manufac- turers' competitive edge in the world market because their need to develop and maintain both TCP products as well as TP-4 products would dilute their skill resources. The same thing would happen with Option 3. Although -58-

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none of the options would affect the world market for TP-4 greatly, Option 3 would result in a residual market for TOP products in the DOD and re- ated networks. Products made specifically for this market would continue to exist, but with functions limited to this specific market, the products would lack some of the advantages of large-scale production and product develop meet. 1 -59- :

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