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1.1 root 1: % \begin{bwslide}
2: %\part {PRESENTATION SERVICES}\bf
3: %\end{bwslide}
4:
5:
6: \begin{bwslide}
7: \part {PRESENTATION SERVICES}\bf
8:
9: %\vskip.5in
10: \diagram[p]{figureA-7}
11: \end{bwslide}
12:
13:
14: \begin{bwslide}
15: \ctitle {PRESENTATION LAYER\\PURPOSE}
16:
17: \begin{nrtc}
18: \item COMBINES
19: \begin{nrtc}
20: \item STRUCTURING ASPECTS OF ABSTRACT SYNTAX
21: \item COMMUNICATIONS CONTROL OF SESSION SERVICES
22: \end{nrtc}
23: \item EXCHANGES DATA STRUCTURES OVER SESSION DIALOGUES
24: \end{nrtc}
25: \end{bwslide}
26:
27:
28: \begin{bwslide}
29: \ctitle {THE PRESENTATION LAYER}
30:
31: \vskip.5in
32: {\tiny\diagram[p]{figureA-23}}
33: \end{bwslide}
34:
35:
36: \begin{bwslide}
37: \ctitle {PRESENTATION}
38:
39: \begin{nrtc}
40: \item QUITE SIMPLE COMPARED TO SESSION SERVICE
41: \begin{nrtc}
42: \item {\em ALTHOUGH IT MAY NOT APPEAR SO}
43: \end{nrtc}
44: %\item PRIMITIVES PREFIXED WITH {\em P---\ldots}
45: \end{nrtc}
46: \end{bwslide}
47:
48:
49: % \begin{bwslide}
50: %\ctitle {USERS}
51: %
52: %\begin{nrtc}
53: %\item {\em PS--users} ARE APPLICATION SERVICE ELEMENTS (ASEs)
54: %\item PRESENTATION VIEW: SINGLE ENTITY IS A {\em PS--user}
55: %\item APPLICATION VIEW: MANY ASEs COOPERATE TO APPEAR AS ONE {\em PS-user}
56: %\end{nrtc}
57: %\end{bwslide}
58:
59:
60: % \begin{bwslide}
61: %\ctitle {\em PS-users}
62: %
63: %\begin{nrtc}
64: %\item CONNECTION ESTABLISHMENT
65: % \begin{nrtc}
66: % \item CALLING {\em PS-user}
67: % \item CALLED {\em PS-user}
68: % \end{nrtc}
69: %\item ACTION INITIATION
70: % \begin{nrtc}
71: % \item REQUESTING {\em PS-user}
72: % \item ACCEPTING {\em PS-user}
73: % \end{nrtc}
74: %\item CONNECTIONS ARE SYMMETRIC
75: %\end{nrtc}
76: %\end{bwslide}
77:
78:
79: % \begin{bwslide}
80: %\ctitle {ADDRESSING}
81: %
82: %\begin{nrtc}
83: %\item USER ADDRESSED AT PRESENTATION SERVICE ACCESS POINT (PSAP)
84: % \begin{nrtc}
85: % \item PRESENTATION SELECTOR
86: % \item SESSION ADDRESS
87: % \end{nrtc}
88: %\item SELECTOR IS A STRING OF OCTETS
89: %\item SESSION ADDRESS IDENTIFIES A GIVEN PRESENTATION ENTITY
90: %\item PRESENTATION SELECTOR IDENTIFIES A SPECIFIC USER OF THAT ENTITY
91: %\end{nrtc}
92: %\end{bwslide}
93:
94:
95: % \begin{bwslide}
96: %\ctitle {PRESENTATION PROVIDES}
97: %
98: %\begin{nrtc}
99: %\item {\em PRESENTATION} CONTEXT MANAGEMENT
100: %\item {\em SESSION FUNCTIONALITY}
101: %\end{nrtc}
102: %\end{bwslide}
103:
104:
105: \begin{bwslide}
106: \ctitle {PRESENTATION CONTEXTS}
107:
108: \begin{nrtc}
109: \item A CONTEXT IS A PAIRING OF:
110: \begin{nrtc}
111: \item A SET OF DATA STRUCTURE DEFINITIONS (ABSTRACT SYNTAX)
112: \item RULES FOR ENCODING THOSE DATA STRUCTURES ON THE NETWORK
113: (TRANSFER SYNTAX)
114: \end{nrtc}
115: \item PRESENTATION CONTEXT IDENTIFIER (PCI)
116: \begin{nrtc}
117: \item {\small (DIFFERENT THAN PROTOCOL CONTROL INFORMATION --- PCI)}
118: \end{nrtc}
119: \item USER DATA GIVEN TO PRESENTATION IS MARKED WITH A CONTEXT
120: \begin{nrtc}
121: \item FOR A GIVEN ASE, e.g., ASSOCIATION CONTROL
122: \end{nrtc}
123: \item CONTEXTS MAY BE DEFINED OR REMOVED FOLLOWING PRESENTATION CONNECTION
124: ESTABLISHMENT
125: \item EVENTS MAY ALTER DEFINED CONTEXT SET (e.g., RESYNCHRONIZATION)
126: \end{nrtc}
127: \end{bwslide}
128:
129:
130: \begin{bwslide}
131: \ctitle {TRANSFER SYNTAXS}
132:
133: \begin{nrtc}
134: \item PRESENTATION NEGOTIATES TRANSFER SYNTAX ASSOCIATED WITH EACH
135: ABSTRACT SYNTAX
136: \begin{nrtc}
137: \item THIS IS AN EASY JOB, \underline{TODAY}!
138: \end{nrtc}
139: \item THE {\em BER} IS THE ONLY TRANSFER SYNTAX DEFINED TODAY
140: \item {\em ASN.1} IS THE ONLY ABSTRACT SYNTAX DEFINED TODAY
141: \item APPLICATION MAY NEED TO ``HINT'' AT TRANSFER SYNTAX {\em IN THE FUTURE}
142: \end{nrtc}
143: \end{bwslide}
144:
145:
146: \begin{bwslide}
147: \ctitle {DEFINED CONTEXT SET (DCS)}
148:
149: \begin{nrtc}
150: \item SET OF CONTEXTS BEING USED ON CONNECTION
151: \item INITIALLY SUPPLIED BY USER
152: \item NEGOTIATED BY PRESENTATION
153: \end{nrtc}
154: \end{bwslide}
155:
156:
157: % \begin{note}
158: %provide negotiation scenario?
159: %\end{note}
160:
161:
162: \begin{bwslide}
163: \ctitle {CONTEXT MANAGEMENT}
164:
165: \begin{nrtc}
166: \item \underline{OPTIONAL} FUNCTIONALITY TO CHANGE {\em DCS} DURING CONNECTION
167: \item NEGOTIATION PROCESS DURING CONNECTION SAME AS ORIGINAL, {\em IF AVAILABLE}
168: \end{nrtc}
169: \end{bwslide}
170:
171:
172: % \begin{bwslide}
173: %\ctitle {FUNCTIONAL UNITS}
174: %
175: %\begin{nrtc}
176: %\item KERNEL
177: % \begin{nrtc}
178: % \item MANDATORY
179: % \end{nrtc}
180: %\item CONTEXT MANAGEMENT
181: % \begin{nrtc}
182: % \item OPTIONAL
183: % \end{nrtc}
184: %\item CONTEXT RESTORATION
185: % \begin{nrtc}
186: % \item OPTIONAL
187: % \item {\em ONLY POSSIBLE IF CONTEXT MANAGEMENT AVAILABLE}
188: % \end{nrtc}
189: %\end{nrtc}
190: %\end{bwslide}
191:
192:
193: % \begin{bwslide}
194: %\ctitle {PRESENTATION USER DATA}
195: %
196: %\begin{nrtc}
197: %\item PRESENTATION SERVICE DATA UNIT (PSDU)
198: %\item COMPOSED OF:
199: % \begin{nrtc}
200: % \item PRESENTATION DATA VALUES
201: % \end{nrtc}
202: %\item {\em EXCEPTION}: EXPEDITED DATA IS ALWAYS SENT IN THE DEFAULT CONTEXT
203: %\end{nrtc}
204: %\end{bwslide}
205:
206:
207: % \begin{bwslide}
208: %\ctitle {PRESENTATION DATA VALUES}
209: %
210: %\begin{nrtc}
211: %\item EACH HAS AN ASSOCIATED PCI
212: %\item IMPLEMENTOR MAY CHOOSE LOCAL REPRESENTATION
213: %\item ORDER OF VALUES IS PRESERVED IN PSDUs
214: %\item MAY CONTAIN DATA OF ANOTHER ABSTRACT SYNTAX
215: % \begin{nrtc}
216: % \item BUT ONLY ONE TRANSFER SYNTAX USED
217: % \end{nrtc}
218: %\end{nrtc}
219: %\end{bwslide}
220:
221:
222: % \begin{bwslide}
223: %\ctitle {?}
224: %
225: %THE PRESENTATION SERVICE HAS NO EXPLICIT KNOWLEDGE OF ASN.1 OR THE BER.
226: %BUT THE PROVIDER USES BOTH CONCEPTS INTERNALLY.
227: %
228: %PROVIDE SOME SUPPORT FOR THIS IDEA.
229: %\end{bwslide}
230:
231:
232: % \begin{bwslide}
233: %\ctitle {ACCESS TO SESSION SERVICE}
234: %
235: %\begin{nrtc}
236: %\item PRESENTATION HAS A STRAIGHT FORWARD MAPPING TO THE SESSION SERVICE
237: %\item SESSION PRIMITIVES HAVE CORRESPONDING PRESENTATION PRIMITIVES
238: %\item PRESENTATION REQUIREMENTS IMPLY REQUIREMENTS ON SESSION FUNCTIONAL UNITS
239: %\item SOME PRESENTATION CONCEPTS ARE ``PASS--THROUGH'' TO SESSION
240: % \begin{nrtc}
241: % \item e.g., QUALITY OF SERVICE
242: % \end{nrtc}
243: %\end{nrtc}
244: %\end{bwslide}
245:
246:
247: \begin{bwslide}
248: \ctitle {IMPLEMENTATION CONSIDERATIONS}
249:
250: \begin{nrtc}
251: \item STRONG MAPPING TO SESSION SIMPLIFIES PRESENTATION IMPLEMENTATION
252: \item PRESENTATION STATE MACHINE OFTEN PROVIDED IMPLICITLY BY SESSION
253: \item EXTRA WORK OVER SESSION:
254: \begin{nrtc}
255: \item TRANSFORMING PSDUs INTO SSDUs \& BACK
256: \end{nrtc}
257: \end{nrtc}
258: \end{bwslide}
259:
260:
261: \begin{bwslide}
262: \ctitle {IMPLEMENTATION CONSIDERATIONS (cont.)}
263:
264: \begin{nrtc}
265: \item PRESENTATION PRIMITIVES MAP EASILY TO PROCEDURE CALLS/RETURNS
266: \item USING SESSION TO ENFORCE MOST RULES MOST PRESENTATION PRIMITIVES
267: ARE SIMPLE
268: \begin{nrtc}
269: \item CHECK ANY SPECIFIC PRESENTATION INTERFACE POLICIES
270: \item MAP PSDU TO SSDU
271: \item INVOKE CORRESPONDING SESSION SERVICE
272: \end{nrtc}
273: \end{nrtc}
274: \end{bwslide}
275:
276:
277: % \begin{bwslide}
278: %\ctitle {ENCODINGS}
279: %
280: %\begin{nrtc}
281: %\item ASN.1 USED TO DEFINE PPDUs
282: %\item THE BER IS USED TO ``SERIALIZE'' PPDUs TO \& FROM SSDUs
283: %\end{nrtc}
284: %\end{bwslide}
285:
286:
287: \begin{bwslide}
288: \ctitle {LIGHTWEIGHT PRESENTATION PROTOCOL}
289:
290: \vskip.5in
291: \diagram[p]{figureA-25}
292: \end{bwslide}
293:
294:
295: \begin{bwslide}
296: \ctitle {LIGHTWEIGHT PRESENTATION (cont.)}
297:
298: \begin{nrtc}
299: \item INTERNET COMMUNITY CREATION
300: \item STREAM--LINED PRESENTATION \& SESSION SERVICES
301: \item AVOIDS CUMBERSOME OVERHEAD OF COMPLETE SERVICES
302: \item INTENDED FOR USE BY SPECIFIC ASEs
303: \item WILL \underline{NOT} SATISFY ALL ASE REQUIREMENTS
304: \end{nrtc}
305: \end{bwslide}
306:
307:
308: \begin{bwslide}
309: \ctitle {LIGHTWEIGHT PRESENTATION (cont.)}
310:
311: \begin{nrtc}
312: \item SUPPLIES FUNCTIONALITY REQUIRED BY:
313: \begin{nrtc}
314: \item ASSOCIATION CONTROL
315: \item REMOTE OPERATIONS
316: \end{nrtc}
317: \item SATISFIES EXISTING OSI APPLICATIONS
318: \begin{nrtc}
319: \item NETWORK MANAGEMENT ({\em ORIGINAL MOTIVATION})
320: \item DIRECTORY SERVICES
321: \end{nrtc}
322: \item SHOWN TO BE UP TO TWICE AS PERFORMANT
323: \begin{nrtc}
324: \item (PLUS MUCH SMALLER APPLICATION PROGRAMS)
325: \end{nrtc}
326: \end{nrtc}
327: \end{bwslide}
328:
329:
330: \begin{bwslide}
331: \ctitle {LIGHTWEIGHT PRESENTATION (cont.)}
332:
333: \begin{nrtc}
334: \item PROVIDES IDENTICAL APPLICATION PROGRAM INTERFACE
335: \begin{nrtc}
336: \item IMPLIES APPLICATIONS CAN BE EASILY PORTED TO ``REAL'' OSI
337: \end{nrtc}
338: \item \underline{PROTOCOL} DOES \underline{NOT} INTEROPERATE
339: WITH ``REAL'' OSI APPLICATIONS
340: \begin{nrtc}
341: \item WOULD REQUIRE AN APPLICATION LAYER GATEWAY TO AN OSI STACK
342: \end{nrtc}
343: \end{nrtc}
344: \end{bwslide}
345:
346:
347: % \begin{bwslide}
348: %\ctitle {USER CONSIDERATIONS}
349: %
350: %\begin{nrtc}
351: %\item {\em P-CONNECT}
352: % \begin{nrtc}
353: % \item PASSING A DATA VALUE WITH AN ABSTRACT SYNTAX UNKNOWN TO
354: % THE RESPONDER MAY RESULT IN A REJECT
355: % \end{nrtc}
356: %\end{nrtc}
357: %\end{bwslide}
358:
359:
360: \begin{bwslide}
361: \ctitle {GENERAL POINTS}
362:
363: PRESENTATION, SYNTAXES, AND CONTEXTS WHILE NOT VERY COMPLEX CAN PRESENT A GREAT
364: DEAL OF CONFUSION. SORTING OUT THE TERMS AND THEIR SIGNIFICANCE WILL MAKE ANY
365: OSI APPLICATION DEVELOPERS LIFE MUCH EASIER. UNDERSTANDING THESE CONCEPTS IS
366: VITAL TO SUCCESSFUL INTEROPERABILITY TESTING.
367: \end{bwslide}
368:
369:
370: % \begin{bwslide}
371: %\ctitle {PURPOSE}
372: %
373: %\begin{nrtc}
374: %\item SEMANTIC EQUIVALENCE
375: % \begin{nrtc}
376: % \item SENDING ENTITY
377: % \item RECEIVING ENTITY
378: % \end{nrtc}
379: %\end{nrtc}
380: %\end{bwslide}
381:
382:
383: % \begin{bwslide}
384: %\ctitle{PROBLEMS}
385: %
386: %\begin{nrtc}
387: %\item REPRESENTATION OF PRIMATIVE VALUES
388: % \begin{nrtc}
389: % \item INTEGERS
390: % \begin{nrtc}
391: % \item 1's OR 2's COMPLEMENT
392: % \item BIT ORDERING
393: % \item RANGE RESTRICTIONS
394: % \end{nrtc}
395: % \item ENUMERATIONS, SCALARS
396: % \item CHARACTER SETS
397: % \item FLOATING POINT!
398: % \end{nrtc}
399: %\item REPRESENTATION OF CONSTRUCTORS
400: % \begin{nrtc}
401: % \item ARRAY, RECORDS, FILES, ...
402: % \begin{nrtc}
403: % \item ORDERING, PACKING, ALIGNMENT
404: % \end{nrtc}
405: % \item VARIANTS, CHOICES, etc.
406: % \end{nrtc}
407: %\end{nrtc}
408: %\end{bwslide}
409:
410:
411: % \begin{bwslide}
412: %\ctitle {REFERENCES}
413: %
414: %\begin{description}
415: %\item[ISO/IEC 8322:] Basic Connection Oriented Presentation
416: % Service Definition
417: %\item[ISO/IEC 8323:] Basic Connection Oriented Presentation
418: % Protocol Specification
419: %\end{description}
420: %\end{bwslide}
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