The ns Manual (formerly ns Notes and Documentation)1 - NM Lab at ...
The ns Manual (formerly ns Notes and Documentation)1 - NM Lab at ... The ns Manual (formerly ns Notes and Documentation)1 - NM Lab at ...
The routine send-periodic-update{} invokes send-updates{} to send the actual updates. It then reschedulessending the next periodic update after advertInterval jittered slightly to avoid possible synchronization effects.send-updates{} will send updates to a select set of peers. If any of the routes at that node have changed, or for periodicupdates, the procedure will send updates to all peers. Otherwise, if some incident links have just recovered, the procedurewill send updates to the adjacent peers on those incident links only.send-updates{} uses the procedure send-to-peer{} to send the actual updates. This procedure packages the update,taking the split-horizon and poison reverse mechanisms into account. It invokes the instproc-like, send-update{} (Notethe singular case) to send the actual update. The actual route update is stored in the class variable msg_ indexed by a nondecreasinginteger as index. The instproc-like only sends the index to msg_ to the remote peer. This eliminates the need toconvert from OTcl strings to alternate formats and back.When a peer receives a route update it first checks to determine if the update from differs from the previous ones. The agentwill compute new routes if the update contains new information.29.6 Unicast routing objectsRoutelogic and rtObject are two objects that are significant to unicast routing in ns. Routelogic, essentially, represents therouting table that is created and maintained centrally for every unicast simulation. rtObject is the object that every nodetaking part in dynamic unicast routing, has an instance of. Note that nodes will not have an instance of this object if Sessionrouting is done as a detailed routing protocol is not being simulated in this case. The methods for RouteLogic and rtObjectare described in the next section.29.7 Commands at a glanceFollowing is a list of unicast routing related commands used in simulation scripts:$ns_ rtproto where defines the type of routing protocol to be used, like Static, Manual, Session , DV etc. args may definethe list of nodes on which the protocol is to be run. The node list defaults to all nodes in the topology.Internal methods:$ns_ compute-routesThis command computes next_hop information for all nodes in the topology using the topology connectivity. Thisnext_hop info is then used to populate the node classifiers or the routing tables. compute-routes calls compute-flat-routesor compute-hier-routes depending on the type of addressing being used for the simulation.$ns_ get-routelogicThis returns a handle to the RouteLogic object (the routing table), if one has been created. Otherwise a new routing tableobject is created.$ns_ dump-routelogic-nh259
This dumps next hop information in the routing table.$ns_ dump-routelogic-distanceThis dumps the distance information in the routing table.$node add-route This is a method used to add routing entries (nexthop information) in the node’s routing table. The nexthop to fromthis node is the object and this info is added to the node’s classifier.$routelogic lookup Returns the id of the node that is the next hop from the node with id srcid to the node with id destid.$routelogic dump Dump the routing tables of all nodes whose id is less than nodeid. Node ids are typically assigned to nodes in ascendingfashion starting from 0 by their order of creation.rtobject dump-routes Dump the routing table to the output channel specified by fileID. fileID must be a file handle returned by the Tcl opencommand and it must have been opened for writing.$rtobject rtProto?Returns a handle to the routing protocol agent specified by proto if it exists at that node. Returns an empty string otherwise.$rtobject nextHop?Returns the id of the node that is the next hop to the destination specified by the node id, .$rtobject rtpref?destIDReturns the preference for the route to destination node given by destid.$rtobject metric?destIDReturns metric for the route to destid.260
- Page 209 and 210: Chapter 22DelayBox: Per-Flow Delay
- Page 211 and 212: $ns attach-agent $n_sink $sink# mak
- Page 213 and 214: Chapter 23Changes made to the IEEE
- Page 215 and 216: Part IIISupport214
- Page 217 and 218: endenddocument pargvcPrint out argc
- Page 219 and 220: 24.4.2 Memory Conservation TipsSome
- Page 221 and 222: Chapter 25Mathematical SupportThe s
- Page 223 and 224: set run [lindex $argv 0]}if {$run <
- Page 225 and 226: }$sizeRNG next-substream# print the
- Page 227 and 228: protected:RNG* rng_;};Classes deriv
- Page 229 and 230: ns-random is implemented in ~ns/mis
- Page 231 and 232: Chapter 26Trace and Monitoring Supp
- Page 233 and 234: The monitor-queue function is const
- Page 235 and 236: also used to accumulate packet drop
- Page 237 and 238: }name,th->size(),flags,iph->flowid(
- Page 239 and 240: PT_TORA,PT_DSR,PT_AODV,// insert ne
- Page 241 and 242: The QueueMonitor class is not deriv
- Page 243 and 244: $ns_ trace-all This is the command
- Page 245 and 246: Chapter 27Test Suite SupportThe ns
- Page 247 and 248: ... ...}$ns_ at $opt(stop).1 "$self
- Page 249 and 250: Example: To enable debugging in Que
- Page 251 and 252: Chapter 29Unicast RoutingThis secti
- Page 253 and 254: Asymmetric Routing Asymmetric routi
- Page 255 and 256: class RouteLogic This class defines
- Page 257 and 258: — The procedure init-all{} is a g
- Page 259: Global Actions Once the detailed ac
- Page 263 and 264: $ns mrtproto ST;# specify shared tr
- Page 265 and 266: Dense Mode The Dense Mode protocol
- Page 267 and 268: and unique label (id). Thus, “inc
- Page 269 and 270: add-iif{ifid link},add-oif{link if}
- Page 271 and 272: CtrMcastComp is the centralised mul
- Page 273 and 274: $ns_ mrtproto This command specifi
- Page 275 and 276: Chapter 31Network DynamicsThis chap
- Page 277 and 278: v 0.8123 link-up 3 5v 0.8123 link-u
- Page 279 and 280: The first argument is the time at w
- Page 281 and 282: $ns_ rtmodel This command defines
- Page 283 and 284: $ns set-address-format hierarchical
- Page 285 and 286: 32.4 Hierarchical Routing with Sess
- Page 287 and 288: Chapter 33UDP Agents33.1 UDP Agents
- Page 289 and 290: Chapter 34TCP AgentsThis section de
- Page 291 and 292: set ns [new Simulator]set node1 [$n
- Page 293 and 294: 34.2.1 The Base TCP SinkThe base TC
- Page 295 and 296: Agent/TCP/FullTcp set dupseg_fix_ t
- Page 297 and 298: 34.5 Tracing TCP DynamicsThe behavi
- Page 299 and 300: Chapter 35SCTP AgentsThis chapter d
- Page 301 and 302: Figure 35.1: Example of a Multihome
- Page 303 and 304: Note: the actual value of these tra
- Page 305 and 306: 1.526624 1 4 sctp 1500 -------D 0 1
- Page 307 and 308: $ns at 5.0 "finish"$ns run35.5.2 Mu
- Page 309 and 310: Chapter 36Agent/SRMThis chapter des
This dumps next hop inform<strong>at</strong>ion in the routing table.$<strong>ns</strong>_ dump-routelogic-distanceThis dumps the distance inform<strong>at</strong>ion in the routing table.$node add-route This is a method used to add routing entries (nexthop inform<strong>at</strong>ion) in the node’s routing table. <strong>The</strong> nexthop to fromthis node is the object <strong>and</strong> this info is added to the node’s classifier.$routelogic lookup Retur<strong>ns</strong> the id of the node th<strong>at</strong> is the next hop from the node with id srcid to the node with id destid.$routelogic dump Dump the routing tables of all nodes whose id is less than nodeid. Node ids are typically assigned to nodes in ascendingfashion starting from 0 by their order of cre<strong>at</strong>ion.rtobject dump-routes Dump the routing table to the output channel specified by fileID. fileID must be a file h<strong>and</strong>le returned by the Tcl opencomm<strong>and</strong> <strong>and</strong> it must have been opened for writing.$rtobject rtProto?Retur<strong>ns</strong> a h<strong>and</strong>le to the routing protocol agent specified by proto if it exists <strong>at</strong> th<strong>at</strong> node. Retur<strong>ns</strong> an empty string otherwise.$rtobject nextHop?Retur<strong>ns</strong> the id of the node th<strong>at</strong> is the next hop to the destin<strong>at</strong>ion specified by the node id, .$rtobject rtpref?destIDRetur<strong>ns</strong> the preference for the route to destin<strong>at</strong>ion node given by destid.$rtobject metric?destIDRetur<strong>ns</strong> metric for the route to destid.260
Change language