w i re 1 css ne two rks, ii n d opt ica I switching. He has organizcd several work- .... tral density (PSD) of signals (Appendix. A) and exactly how binary, M-ary, and.
BOOKREVIEWS (Continued fr-om page 22)
OSPF routers, the reader is introduced to such main concepts as flooding, setting up a hierarchy, and routing calculations. C h a p t e r 4 provides p o r t i n g considerations, while Chapter 5 introduces s o m e basic classes for storing, sorting, and quick searching of various d a t a elements. C h a p t e r 6, one of t h e most interesting, proposes the internal structure of the link-state database, the content of which is used for route calculations. This c h a p t e r also provides m e t h o d s of d a t a b a s e m a n a g e m e n t . Chapter 7 shows in detail in which circumstances a n d how a r o u t e r generates link-state advertisements (LSAs). Chapters 8 and 9 address other important functions: the process of discovery a n d m a i n t e n a n c e of r o u t i n g neighbors (setting u p ncighbor relationships), a n d t h e reliable flooding mechanism which ensurcs a consistent view of the network by all routers and is critical to ensuring rcachability and loop-free routing. Chapter I O clarifies the concept of OSPF areas, area aggrcgatcs, and virtual links, and shows how thcsc can bc implemented i n the soft-
ware. It also discusses t h e e x t e r n a l routing and stub areas. C h a p t e r 11 is devoted to routing calculations based on the raw topology data of the l i n k state database. These include consistency checks of the LSAs, and intra-, inter-, and transit-area routing calculations including equal cost paths (multipath calculations). The implementation of m u l t i c a s t e x t e n s i o n s follows in C h a p t e r 12. C h a p t e r 13 discusses a rich set of configuration p a r a m e t e r s that affect the properties and dynamics of the protocol. The attached CD-ROM is very interesting a n d valuable. I t c o n t a i n s t h e c o m p l e t e C + + s o u r c e c o d e of t h e OSPF routing daemon for Linux, and the OSPF routing simulator ospf-sim, which can be run under Linux or Windows. l'hesc add-ons perfectly corrcspond to the contcnt of the hook and complement it. C h a p t e r 15 dcscribcs the functionality of thc simulator. S u m ni a r i z i n g , t h e book p r o v i d c s extensivc high-quality documentation f o r quality s o u r c c c o d c . For O S P F e x p c r t s i t is a n u l t i m a t e s o u r c e f o r details of complex interactions prcscnt i n the rc a I - t i me d i s t ri bu t cd pro t oco I .
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For distributed networking software developers it is a good case study of how to design such a complex system in a structured way. T h e book also provides numerous interesting techniques t h a t o p t i m i z e t h e efficiency of t h c i m p l e m e n t a t i o n , a n d hints for t h o s e who would like to port the software to other hardware platforms or operating systems.
DIGITALMODULATION TECHNIQUES FUQINXIONG, ARTECHHOUSE,2000, ISBN: 0-89006-970-0, 674 PAGES REVIEWEDBY ERIC BOBINSKY Digital Modulntion Techniques is a s e If - c o n t a i n e d , c o m p r e h e n s ive a 11d detailed synthesis of nearly cvery digital modulation technique in use today. The author, a professor of electrical engineering at Cleveland State Univcrsity'z Fenn College of Enginccring, has S L I C ccedcd admirably at the ambitious t x k of bringing togcthcr information that is largely scattcrcd throughout t h c engineering litcriiturc :tiid prcscnting i t i n ;I ( C o i i r i i i i t c ~ t lO I I p
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