Survivable Signalling Network simulator

Abstract

AbstudThe &uvivable Signding N e t w d (SSN)l'l, 1 2 ' , beiq developed for the united Stated Govanment by AT&T, providsl a m b t signaling ne& SSN, based on the ATBT Switched Network (ASN). consists of signsling linka betwan 4BsS iwitchhy systems, a Signal Transfer point (SIT) cqubility in w h 4ESS. and an adaptive routiry capability m the STP fimction to dyMmicly m!o&gue the signaling network. SSN u m a d i s m i bodcrst algorithm to dissembte the network status inIomution throughout the network and a " u m hop algorithm to find muting paths for d & W m Signal InCSS8mollg 6witches. 1. I.bod.dla Becwse of the carnplexitica of SSN. this simulator has ken developed for extensive simulations to stdy the SSNalgaithm mdthenetworkperfommeinoxderto mestthepcJf--. The simulator i m p l a n d the SSN algorithm, took the ASN d w m into rcounf and d & r e d &xluate delay infmnrtian and SSN parunetar. md simulated the whole network U vuioua damage scamios and network topologica. crplbilitier. such as computing the network respomse time to danag&covery md network connectivity, and ICCO~S W e d mtwork activities. such (16 the routing Elbly hirtay Bkr of events and Link State Packets (LSR). The simulator implements efficient data stnrturar and algorithm, uses a flexible i n p t f m a t md llro p v i d a a flialdly gaphiCS mterfrce for sun worlrrtalim.In this ppa, the SSN broadcast algorithm is briefly dacribed6rsLThemoderimdimplmmIationofthe simulator pa tkn eql& The input format md simulrtion cqmbimica pa deMikd F i y , simut.lionua andrminrdts p c~s e d .The simulator pvides a rich set of S h u l a t i o n O . t h e d S S N w & d t k . AThe algorithm W e s eventdriven and clockdriven e m q u h every node Booding l i d status m f d m m LSR to its neighbors to ensure evay node hu the most updated md consistmt link status i n f d a An LSP contrins four data categories: (1) the Bolnce ia. (2) the link slmls of the sourcenodh (3) the sequam number of the LSP. md (4) the age of the LSP.If no event occurs m a MAX-INT interval, a node gewmted md broa&asts a new ISP to its mighbon (periodic generation of UPS). As a link changes ita status, thenodes oneached of thelinkholdwtthis event in LSPs to each of their neighbors. when a node received a LSP, it " p r e s the sequenw number of h e received LSP with the previowly received LSP hrm the node with the same source id in its LSP table. If the receiving node updates its LSP and Link Status Tables and the LSP is bmpdcrsted. Obmise, the reoeivad LSP is discardsd.The tnnSmitting U P S over a link by one W should be separated by a THRUlTLB-INT amount of time. An LSP h a an initial age of MAX-AGE which is decremented by an AGE-UNlT of time for uch liak traveled, or stayed in a node's U P Table. If the received LSP caused the receiving node wuts time before recnnpLting I received LSP has a l q e r sequemx "ber, Ihe mini"-hop algolithm.The node that connects to the unavailable qxlates its LSP and Link Statua Tabla. The Timer is set to MIN-INT. When this timer e LSP is g m d and hadcastal. A U W...