update simple example

README.md

@@ -18,17 +18,48 @@ SyNET is invoked using the following command
 
 
 ### Example
-```bash
-TOPO=gridrand4; REQ=5; PROT=bgp; time ./synet.py -i examples/CAV-experiments/$TOPO-$PROT-$REQ.logic  -r examples/CAV-experiments/$TOPO-$PROT-$REQ-req.logic -m $PROT
-```
+
+A simple example is provided at `examples/simple.logic` of a topology with 3 nodes connected in a triangle shape.
+In this example, external BGP traffic is learned via `R2`.
+A sample requirement over this topology, is to forward the traffic going externally via the path `R1-R3-R2`.
+The requirements are provided in `examples/simple-req.logic`.
+
+To synthesize the configrations for this example, SyNET can be invoked as follow:
 
 ```bash
-TOPO=AttMpls; REQ=1; PROT=bgp; time ./synet.py -i examples/topozoo/$TOPO-$PROT-$REQ.logic  -r examples/topozoo/$TOPO-$PROT-$REQ-req.logic -m $PROT
+./synet.py -i examples/simple.logic -r examples/simple-req.logic -m bgp
 ```
 
+The argument `-i` specifies the input topology. The topology is represented as a set of Datalog predicates.
+For instance. `+SetNode("R1"").` adds a router `R1` to the topology, while `+SetLink("R1_I1", "R2_I1").`
+specifics that there is a link between the two interfaces `R1_I1` and `R2_I1`.
+
+
+The argument `-r` specifices the requirements to be implemented on the given topology.
+The requirement uses the same syntax as the topology file.
+
+The argument `-m` specifices which protocols to use: `static` will only use static routes,
+`ospf` will used static and OSPF routes, and `bgp` will use static, OSPF and BGP routes.
+
+
+
 
 ### Provided Examples:
 We provide two sets of examples. The first set, in `examples/CAV-experiments`, is a set of synthesized grid topologies
 in addition to Internet2 topology. This set were used in evaluating SyNET for CAV'17 paper.
+
+You can run these examples via:
+
+```bash
+TOPO=gridrand4; REQ=5; PROT=bgp; time ./synet.py -i examples/CAV-experiments/$TOPO-$PROT-$REQ.logic  -r examples/CAV-experiments/$TOPO-$PROT-$REQ-req.logic -m $PROT
+```
+
+
 The second set, are more realistic examples take from [The Internet Topology Zoo](http://www.topology-zoo.org/) and located
 at `examples/topozoo`.
+
+You can run these examples via:
+
+```bash
+TOPO=AttMpls; REQ=1; PROT=bgp; time ./synet.py -i examples/topozoo/$TOPO-$PROT-$REQ.logic  -r examples/topozoo/$TOPO-$PROT-$REQ-req.logic -m $PROT
+```

examples/simple-req.logic

@@ -1,5 +1,5 @@
 +Fwd("R2_N1", "R1", "R3", "ospf").
 +Fwd("R2_N1", "R3", "R2", "ospf").
 
-+Fwd("Google", "R1", "R3", "bgp").
-+Fwd("Google", "R3", "R2", "bgp").
++Fwd("ExtTraffic", "R1", "R3", "bgp").
++Fwd("ExtTraffic", "R3", "R2", "bgp").

examples/simple.logic

@@ -23,4 +23,4 @@
 
 
 +SetNetwork("R2", "R2_N1").
-+SetBGPAnnouncement("R2", "R2_N1", "Google", "1;2;3", 3).
++SetBGPAnnouncement("R2", "R2_N1", "ExtTraffic", "1;2;3", 3).