Agents used to monitor and control optical switches
Creating on demand an optical path/tree for end user applications
In the MonALISA framework we developed dedicated modules and agents to
monitor and control Optical Switches. These modules are used now for
the CALIENT switch at CALTECH and the GLIMMERGLASS switch at
CERN. The monitoring modules use the TL1 language to communicate
with the switch and they are used to collect specific monitoring
information. The state of each link and any change in the system is
reported to dedicated MonALISA agents which are in fact dynamically
loadable modules running inside MonALISA services.
The distributed set of these MonALISA agents is used to control the
system. They use the discovery mechanism to find each other and they
communicate between them using the Proxy Services. Each proxy service
can handle ~1000 messages /s and the architecture is using more than
one such service to achieve a reliable communication between agents.
The agent system is used to create a global path or tree as it
knows the state of each link, inter-site connections and
the cross connections. The routing algorithm provides global
optimization and can be extended to handle priorities and pre
The system is integrated in a reliable and secure way with the
end user applications and provides simple shell-like
commands to map global connections and to create an optical path / tree
on demand for any data transfer application.
A schematic view of how the entire system works is shown in the figure below:
Each station having an optical network
card runs a MonALISA demon. This demon does the discovery of MonALISA
services and the optical control agents and at the same time is used
to provide user authentication ( using X509 certificates) and
secure connection with at least one agent. The demon can
use any of the agents running on different MonALISA services. The
demon takes the user commands and transfer them to the agent system
as well as the answers using the authenticated and encrypted channel.
The system also provides a shell like command, ml_path, which creates an on demand optical path for any user defined application which
then can use it .
Details to configure the monitoring modules, Optical Switch Agent and Optical Switch Daemon :
When an optical path is required
by an user or application the agent system establish it in less than 1
second, independent of how many switches are involved and
were they are located. In the case when all the system
involved are on the
same LAN, the time to create the path is ~ 150 ms.
The entire system is monitored in real-time and it presents the
state and transitions for each port and link .
We partitioned both switches ( CALIENT and GLIMMERGLASS) in 4
units , with physical cross connects to simulate 8 independent switches.
Each such unit is monitored and controlled by one MonALISA service.