ALTO SPCE (Simple Path Computation Engine)

The ALTO SPCE module provides a simple path computation engine for ALTO and other projects. It works in the OpenDaylight(ODL) SDN Controller.

Installation

One prerequisite for installing ALTO SPCE is that the ODL development environment should be setup by following this link.

With this prerequisite satisfied, execute mvn clean install in the directory of alto-spce project to start the installation. After the installation, you can execute ./karaf/target/assembly/bin/karaf to start the alto-spce with ODL.

Deployment

You can also deploy this module into a running ODL controller without stopping the controller, by running ./deploy.sh <distribution_directory>, where <distribution_directory> is the path of your own running ODL distribution.

For example, if you start your ODL controller from /root/distribution-karaf-0.4.0-SNAPSHOT/bin/karaf, you can use the command ./deploy.sh /root/distribution-karaf-0.4.0-SNAP.

NOTE: If you have checked out the latest commit in master branch, you will need a karaf-0.4.1-SNAPSHOT distribution rather than karaf-0.4.0-SNAPSHOT.

And then, you can check whether the features of alto-spce are loaded in your karaf shell as follows:

karaf@root()> feature:list | grep alto-spce

If the features are loaded, you can install them by:

karaf@root()> feature:install odl-alto-spce

Tip:

karaf@root()> log:tail

You could use this command to get the tailing log. If you see AltoSpceProvider Session Initiated!, it means that alto-spce has been installed successfully.

Usage

Prerequisites

Please make sure that your have configured l2switch correctly. Two .xml files below could be found in /karaf/target/assembly/etc/opendaylight/karaf.

In 54-arphandler.xml, please set

<is-proactive-flood-mode>false</is-proactive-flood-mode>

In 58-l2switchmain.xml, please set

<is-learning-only-mode>true</is-learning-only-mode>

Creating a network using Mininet

sudo mn --controller=remote,ip=<Controller IP> --mac --topo=linear,3 --switch ovsk,protocols=OpenFlow13

The command above will create a virtual network consisting of 3 switches. And one host is attached to each switch.

Discover hosts

l2switch uses ARP packets to discover hosts.

If we use mininet, we could use ping to let l2switch get the ARP packets it needs.

mininet> h1 ping h5

After this command, l2switch will discover host1 and host5.

Setup/Remove a path with python-odl library

We have forked python-odl project to support alto-spce. You could get the code here.

＃ Import essential modules.
>>> import odl.instance
>>> import odl.altospce

# Initiate a ODLInstance object.
>>> myodl = odl.instance.ODLInstance("http://127.0.0.1:8181",("admin","admin"))

# Initiate a ALTOSpce object.
>>> myaltospce = odl.altospce.ALTOSpce(server="http://127.0.0.1:8181",credentials=("admin","admin"),odl_instance=myodl)

# Setup a path between host1(10.0.0.1) and host5(10.0.0.5)
>>> myaltospce.path_setup(src="10.0.0.1",dst="10.0.0.5",objective_metrics=["bandwidth"])
{'path': [u'10.0.0.5|openflow:6:3|openflow:5:3|openflow:1:1|openflow:2:1|openflow:3:1|10.0.0.1', u'10.0.0.1|openflow:3:3|openflow:2:3|openflow:1:2|openflow:5:1|openflow:6:1|10.0.0.5'], 'error-code': 'OK'}

# Remove the path between host1(10.0.0.1) and host5(10.0.0.5)
# To identify the path please use the 'path' indicated in myaltospce.path_setup
>>> myaltospce.path_remove(["10.0.0.5|openflow:6:3|openflow:5:3|openflow:1:1|openflow:2:1|openflow:3:1|10.0.0.1","10.0.0.1|openflow:3:3|openflow:2:3|openflow:1:2|openflow:5:1|openflow:6:1|10.0.0.5"])
{'error-code': 'OK'}

Enjoy your alto-spce!

Try the demo system out

We have deploy a demo system in http://alto.yale.edu:8181/index.html and you can try it out. There is a brief usage:

You can setup or remove a path by using python-odl library. Just follow the section "Setup/Remove a path with python-odl library" and replace 127.0.0.1 by alto.yale.edu.

Also you can send a HTTP request like the following template to query ALTO Endpoint Cost Service (ECS):

curl -X POST -H "Content-type: application/alto-endpointcostfilter+json" \
    -d '{"cost-type":{"cost-mode":"numerical","cost-metric":"hopcount"},"endpoints":{"srcs":[<SOURCE_IP_LIST>],"dsts":[<DESTINATION_IP_LIST>]}}' \
    http://alto.yale.edu:8181/alto/endpointcost/default