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这个软件的功能是实现多播协议

Some notes on the test suite

---------------------------

To run the test suites in this directory:

./test-all-red
./test-all-sack
./test-all-schedule
./test-all-tcp
./test-all-red-v1
./test-all-cbq-v1
./test-all-sack-v1
./test-all-v1
./test-all-mcast

OR, just for validation purposes:

./test-all-red quiet
./test-all-sack quiet
./test-all-schedule quiet
./test-all-tcp quiet
./test-all-red-v1 quiet
./test-all-cbq-v1 quiet
./test-all-sack-v1 quiet  
./test-all-v1 quiet
./test-all-mcast

----------------------------

Each of the test suites has been split off into three parts, two of
which are common to all of them.  The common parts are:

I)  The topologies library, stored in topologies.tcl

    This contains a catalogue of topologies used in the test suite.
    Currently, four topologies are defined (net0 through net3).

    Variants of the topology are classified according to the following
    criteria:

    Name of	Qs on Fall-	Dynamic		 Routing	 MultiPath
    Variant	back links	 Links?		Protocol?	Forwarding?
  -----------------------------------------------------------------------------
  <none>	 DropTail	   no		 Static		    NO
  net#-		 DropTail	   yes		 Static		    NO
  net#-Session	 DropTail	   yes		 Session	    NO
  net#-DV	 DropTail	   yes		   DV		    NO
  net#RED-Session   RED		   yes		 Session	    NO
  net#RED-DV	    RED		   yes		   DV		    NO
  net#-DVm0	 DropTail	   no		   DV		    YES
  net#-DVm1	 DropTail	   yes		   DV		    YES
  net#RED-DVm0	 DropTail	   no		   DV		    YES
  net#RED-DVm1	 DropTail	   yes		   DV		    YES

    Note that the RED variants are only defined if the backbone links
    themselves use RED queues.

NOTE:  All tests that use dynamic links (otehr than net#-) use a
tracefile to generate the dynamics events.  The variant net#- currently
uses an Exponential distribution to decide link failure and recovery
times.  It also writes out the trace file `dyn.tr' that is used by the
other variants.

The initialiser for each topology also invokes the instance procedure
``config''.  Each test-suite that is defined could individually
reconfigure a particular topology to suite its needs.  As an example,
this feature is used by the RED test suites to redefine ``linterm_''
for the backbone links in the net2 topology.

The class hierarchy for the topologies is:

    SkelTopology
    |
    +-----  NodeTopology/4nodes
    |       |
    |       +-----  Topology/net0
    |       |       |
    |       |       +-----  Topology/net0-
    |       |       +-----  Topology/net0-Session
    |       |       .
    |       .       .
    |       .       +-----  Topology/net0-DVm1
    |       .
    |
    +-----  NodeTopology/6nodes
    |
    |
    .
    .
    .

The base class for all topologies is the Class SkelTopology.  It
provides one ``useful'' method: add-fallback-links.  The method 
adds fallback paths between pairs of nodes, each link in the path
having identical characteristics.

Different node topology classes are derived from the skeleton topology
class.  There are three currently defined, NodeTopology/4nodes,
NodeTopology/6nodes, and NodeTopology/8nodes.  The node count
indicates the number of nodes in the topology, less those used for
alternate (fallback) paths.  The constructor for each class
instantiates each of the nodes in that topology.

Each topology is then derived from the appropriate NodeTopology.
Four basic topologies are currently defined, Topology/net0 through
Topology/net4. 


1.  net0:  Simple 4 node topology (+1 fallback node) shown as:

		   s1        __ b1 __
		     \      /  0.8Mb \
	      8Mb,5ms \    /   100ms  \ 
		        r1 ------------ k1
              8Mb,5ms /    0.8Mb, 100ms
		     /
		   s2
		Queue limit on <r1, k1> = 6

    Variants defined: net0-, net0-Session, net0-DV, net0-DVm0, and net0-DVm1.
    Cost on link <r1, k1> = 2 for net0-DVm0 and net0-DVm1.

2.  net1:  Another simple 4 node topology (+1 fallback node) shown as:

		   s1        __ b1 __
		     \      /  1.5Mb \
             10Mb,5ms \    /   100ms  \ 
		        r1 ------------ k1
             10Mb,5ms /    1.5Mb, 100ms
		     /
		   s2
		Queue limit on <r1, k1> = 23

    Variants defined: net1-, net1-Session, net1-DV, net1-DVm0, net1-DVm1.
    Cost on link <r1, k1> = 2 for net1-DVm0 and net1-DVm1.

3.  net2: Simple 6 node topology (+1 fallback node) shown as:

	        s1       __b1__       s3
	          \     /1.5 Mb\     /
	  10Mb,2ms \   /  10ms  \   / 10Mb,4ms
	            r1 ---------- r2
	  10Mb,3ms /   1.5Mb 20ms   \ 10Mb,5ms
		  /        RED       \
	        s2                    s4 

    Variants defined: net2-, net2-Session, net2-DV, net2-DVm0, net2-DVm1,
	net2RED-Session, net2RED-DV, net2RED-DVm0, net2RED-DVm1.
    Cost on link <r1, r2> = 2 for *-DVm0, *-DVm1 topology variants.
    Note that, unlike the earlier topologies, the delay on the fallback
    path is the same as the main path,
    		i.e. delay(r1,b1) + delay(b1,r2) = delay(r1,r2).

4.  net3: Simple 8 node topology (+3 fallback nodes) shown as:

            s1       __b1__        __b2__        __b3__       s3
              \     /1.5 Mb\      /1.5 Mb\      /1.5 Mb\     /
      10Mb,2ms \   /  10ms  \    /  10ms  \    /  10ms  \   / 10Mb,4ms
                r1 ---------- r2 ---------- r3 ---------- r4
      10Mb,3ms /   1.5Mb,20ms    1.5Mb 20ms    1.5Mb 20ms   \ 10Mb,5ms
	      /        RED           RED           RED       \
            s2                                                s4 

    Variants defined: net2-, net2-Session, net2-DV, net2-DVm0, net2-DVm1,
	net2RED-Session, net2RED-DV, net2RED-DVm0, net2RED-DVm1.
    Cost on link <r1, r2>, <r2, r3>, <r3, r4> = 2 for *-DVm0, *-DVm1
	topology variants.


II)	misc.tcl defines the base class TestSuite for the tests.
It also defines the routines common to all the test suites.

The class hierarchy for TestSuite is:

	TestSuite
	    |
	    +-----  Test/tahoe
	    |
	    +-----  Test/phaseSack1
	    .
	    .
	    .


The constructor instantiates the appropriate topology.  It will
check that the test will run on the specified topology (or its
variant).  The testName is set to "test:topology".  It also
enables a global trace file, all.tr.

Other routines defined includes the procedure finish.  Unlike in
the ns-1 test suites, this routine does not process the trace
file.  It is upto an external test suite driver to process the
output traces appropriately.  This permits us to flexibly use
either gnuplot, xgraph, or nam as desired.

tcpDump and tcpDumpAll are identical to the ns-1 test suite.
openTrace differs, only in that, it adds the line "v testName
$testName_" to the trace file, out.tr.  Most of the tests gather
traces at the node `r1'.

New routines traceQueues, usage, and runTest are also defined.

	- traceQueues will trace the queues of all links incident on a
	  specified now.  This allows us to trace tcp acks, as well as
	  traffic through alternate paths conveniently.
	- usage is a global procedure that simple prints out the usage
	  relevant for the particular test suite being used.
	- runTest is a static (?) procedure that should be invoked by
	  the test suite.  It checks that the specified test and
	  topology are correctly defined.  It instantiates the test, and
	  then "run"s the test.
	
In addition, misc.tcl will source tcl/test/redefines.tcl, if present.
This allows us (allowed me) to selectively redefine procedures
embedded in ns for debugging, or additional tracing.


III)	The test suites themselves are in individual files.  Currently,
the three are routed, red, and sack.  `routed' is identical to the v2
test suite.  Each of these define a series of tests.  The format of a
test-suite file is:

	set dir [pwd]
	catch "cd tcl/test"
	source misc.tcl
	source topologies.tcl
	catch "cd $dir"

	define test 1
	define test 2
	.
	.
	.
	TestSuite runTest

The template for a typical test is:

---------------------------------------------------------------------------
Class Test/tahoe1 -superclass TestSuite
Test/tahoe1 instproc init topo {
	$self instvar net_ defNet_ test_
	set net_	$topo	;# topology variant to run test on
	set defNet_	net0	;# default topology, used in 2 ways
				 # 1.  topology used, if $topo == ""
				 # 2.  to verify that variant is derived 
				 #     from $defNet_
	set test_	tahoe	;# identity of test.  really an
				 # ns-1 compatibility artifact.

	$self next
}

Test/tahoe1 instproc run {} {
	$self instvar ns_	;# handle for the simulator
	$self instvar node_	;# array of nodes, key = name, val = handle
	$self instvar testName_	;# usually $test_:$net_

	# various Transport configurations, elided for brevity.
	# See actual test suites for details.

	# Trace only the bottleneck link
	#
	# Actually, we now trace all activity at the node around the
	# bottleneck link.  This allows us to track acks, as well
	# packets taking any alternate paths around the bottleneck
	# link.
	#
	$self traceQueues $node_(r1) [$self openTrace 5.0 $testName_]
	$ns_ run
}
---------------------------------------------------------------------------

STATUS OF THE CURRENT TEST SUITES:

test-suite-routed.tcl	This suite is identical to the basic ns-2 test
	suite.   This name is a very bad misnomer, as there is no
	separate routed test suite.

	The telnet test requires a TELNET source, therefore cannot
	currently run.  Hence, it is X'd out.

test-suite-red.tcl	This suite adds additional configuration to the
	net2 topology.  Queue plotting is still untested in ns-2.
	Unlike the finish routine, we have left the trace processing
	routines in plotQueue in the suite.  This suite also redefines
	the tcpDumpAll procedure for its use.

	Tests red_twoway, red_twowaybytes require the TELNET source.
	The flow tests have not even been converted into ns-2 format.
	The tests themselves have been X'd out.

test-suite-sack.tcl	The tests in this routing previously used a
	different tracing routine, openTraces.  It looks like this was
	done to gather traces of returning acks.  The new traceQueues
	procedure should supercede this routine?

	Tests delayedSack and timersSack are commented out.  Is this right?

IV)	In addition, there are driver routines to run these tests, or process
the results.  

1.  ktest-all <suite> [<test> ...]

	Given a <suite>, ktest-all will run all the specified <test>s
	from test-suite-<suite>.tcl, against all the topologies
	defined in topologies in tcl.  If no test is specified, then
	it will run all the tests defined in test-suite-<suite>.tcl.

	The suite will compare the results of all.tr against a
	previously computed result stored in test-output-raw (The result
	is stored the first time the test is run). It will also plot
	the results stored in out.tr.  If $DISPLAY is set, then xgraph
	is used to show on the screen.  Otherwise, gnuplot is used to
	generate a postscript file that is stored in ps-files.

	The program also checks if a new result differs from the
	previously computed result.  Core dumps are saved in the crash
	subdirectory.

2.  rt <suite> <test> [<topology>]

	`rt' will run one <test> from test-suite-<suite>.tcl, for a
	particular <topology>.  If the topology is unspecified, the
	default topology applicable for that test will be used.

The next set of programs are useful in processing trace files.

1.  getrc [-b] [-o outfile] -s node1 [-d node2] [tracefile] 

	Extract trace lines that match certain characteristics.

	-s node1	extract all packets from node1.
	-b -s node1	extract all packets to or from node1.
	-s node1 -d node2	extract packets on link <node1 -> node2>
	-b -s node1 -d node2	extract pkts. on link <node1 <-> node2>.

2.  raw2xg [-a] [tracefile]

	Translate the trace file into a format palatable to xgraph.
	The -a option will extract acks in addition to tcp traffic.

	The conversion algorithms used to be in the finish procedures
	of the ns-1 test suite.

3.  raw2gp [-a] [tracefile]

	Translate the trace file into a format palatable to gnuplot.
	The output data is placed into separate files called `packets',
	`drops', `acks', `link-fails', and `link-recovery'.  The output
	from raw2gp is a set of commands that can processed by gnuplot.
	
Other useful aliases are:

	alias xg	'xgraph -bb -tk -nl -m -x time -y packets'
	alias raw2nam	'awk -f tcl/nam-demo/nstonam.awk'
	alias gvl	'ghostview -landscape -'


As an example, 

	% getrc -s 2 -d 3 test-output-raw/tahoe | raw2xg | xg

will generate the graph of tahoe1, similar to that produced by

	% ./ns test-suite.tcl tahoe1

in the ns-1 test suites.