Riverbed is a WAN optimizer.
This is what you listen as a first line from everyone.
what is WAN optimizer ?
Riverbed simply optimizes or changes or modulates the traffic passing through WAN link.
Riverbed is a separate physical device.
How it looks like ?
But, prior to moving ahead,
Why Riverbed exists or came into the picture ?
Every company needs a WAN link for communication purpose.
WAN link is the leased circuit from a ISP (Internet Service Provider). Bandwidth of the leased circuit is provided by the ISP in a predefined format or standard.
As an example, in India we have the E1’s circuit ( 2.048 Mbps) & in USA we have the T1’s ( 1.54 Mbps ) circuit.
As name suggests, we need to pay for the leased circuit, leased means we are taking something on rent. we need to pay for that. So, every company wants to save the money.
NOW, Riverbed enters into the picture as a money saver.
Riverbed optimizes the data or traffic in such a way that my Bandwidth requirement gets reduced.
Example: If without Riverbed, my bandwidth requirement is 1.5 Mbps. Then definitely after deploying Riverbed, my bandwidth requirement will be less than 1.5 Mbps.
How Riverbed is connected in the network ?
There can be number of methods for Riverbed deployment. we will talk about the most common or simplest one.
In a Enterprise network, when WAN traffic enters, traffic first hits a Layer 3 device, normally a Router. Just after this Layer 3 device, Riverbed is connected, then comes another network device. So, whatever is the traffic, complete traffic will pass through Riverbed. Riverbed as per its mechanism reduces the amount of traffic.
In layman language, this one is similar to the ZIP folder we create for any folder, just to reduce the size.
Here, servers are placed in Corporate Data Center. Different applications are running on servers.
Home users, Users from client location & other users all are coming to Corporate Data Center to access the application.
So, all the users coming through internet will first hit as Layer 3 device, then comes firewall, next to firewall is Riverbed as shown in the diagram.
Example: I am the user & i am trying to access http://www.google.com .
Google must be running on servers & servers must be placed in a Data Center. This traffic will pass through Steelhead Riverbed appliance in between.
FEW KEY POINTS TO NOTE
==> RULES CREATION IN RIVERBED
we can control Riverbed working by creating rules.
Mostly, we do modification with the help of IN-PATH rules.
Most common modification is the creation of PASS-THROUGH rule on the riverbed.
PASS-THROUGH rule simply means bypassing any source or destination from Riverbed.
This is done, if Riverbed is malfunctioning, due to some reason.
If number of rules are present for the same source or destination, Then rules will work exactly similar to Access-list logic, whichever rule comes first, that will be followed.
==> ASYMMETRIC ROUTING
Riverbed do not support Asymmetric routing. Riverbed will show the alarm, if there is Asymmetric routing happening for any source or destination. Asymmetric routing leads to Latency in the network. This is the common problem in most of the networks.
Either remove the Asymmetric routing from the network
Bypass or Pass Though the particular source or destination, which is facing issues due to Asymmetric routing.
Riverbed is not meant for optimizing Voice traffic, UDP traffic. As, voice traffic is considered to be the critical one, we cannot bear latency in case of voice or video traffic.
==> BASIC CONNECTIVITY
Riverbed has got one WAN ( connected to Layer 3 device or WAN device or Customer edge device) & one LAN interface ( connected to a LAN device).
WAN device / Customer edge device ===== Riverbed ====== LAN device
==> SNMP & NFA
we can configure SNMP & NFA on Riverbed.
One limitation is. we cannot configure more than one key on Riverbed to communicate with the SNMP server.