Netconf and Yang

Cisco’s acquisition of Tail-f prompted me to look deeper into what Tail-f does. That in-turn made me dig deeper into Netconf and Yang. Netconf is a device configuration and management protocol and Yang is a modeling language that’s used by Netconf. Yang modeling can also be used outside Netconf’s context. From looking at the history behind Netconf and Yang, I realized that Network management as a whole was a widely ignored topic for quite sometime. The current Network management techniques used by Operators seems to be very arcane and the recent SDN wave has triggered a renewed interest in simplifying Network management. In this blog, I will cover the following:

• Shortcomings of SNMP.
• Netconf and Yang overview with examples.
• Comparison with Ovsdb and Openflow.
• Opendaylight’s use of Yang model
• Tail-f  NCS system’s use of Netconf and Yang.

Network Virtualization – Openstack+ODL integration

In my previous blog, I covered basics of Network Virtualization and overview of commercial solutions available today. The most popular Open source Network Virtualization solution available today is Opendaylight. With the hydrogen release of ODL, ODL can be downloaded in 3 flavors: Base edition, Network Virtualization edition and Service provider edition. Network Virtualization edition adds components like Ovsdb, Opendove, VTN as well as Openstack integration. Ovsdb, Opendove and VTN are different approaches to provide multi-tenant networks. Ovsdb team has put in a nice set of hands-on tutorials for folks wanting to try out Openstack+ODL. I recently tried this out and I was very impressed. In this blog, I will cover my experiences in trying out hands-on Openstack+ODL integration.

Openvswitch and ovsdb

In this blog, I will provide an overview of ovsdb, this is mainly a collection of information from various locations.

Openvswitch is a virtual switch targeted for virtualized environments to switch traffic between VMs.  Its integrated into the latest Linux kernel.

Following are the critical components of Openvswitch.

• ovs-vswitchd, a daemon that implements the switch, along with a companion Linux kernel module for flow-based switching. We can talk to ovs-switchd using Openflow protocol.
• ovsdb-server, a lightweight database server that ovs-vswitchd queries to obtain its configuration. External clients can talk to ovsdb-server using ovsdb management protocol.
• control and management cluster contains client tools to talk to ovsdb-server and ovs-vswitchd.