WAAS and the 'show connection statistics command'

[ryanoneil1980]

HI Everyone

In need of some help in understanding how/where the numbers come from when looking at the how the reduction ratio is calculated.

In an example I can see the following:

                        Original            Optimized                                               

                       -------------------- --------------------   

Bytes Read:      390                   157385   

Bytes Written:   246821               4251   

Total Reduction Ratio: 34.616%

The definition for the reduction ratio in the command reference is "number of bytes that have been read and written on the original (incoming) side and the optimised (outgoing) side".

Taking that logic on the above numbers I see Endpoing ----> WAE reading in 390 bytes ----> WAE sending 4251 bytes optimised to another peer ----> then the WAE recieving the reply from its peer 157385 bytes ---> and sending it 246821 Bytes.

I can understand the last part where the optimised read is lower than the original write, due to the DRE/LZ that is going on but why would the optimised write be higher than the original read??

Likewise here is another example:

                        Original            Optimized                                               

                    -------------------- --------------------   

Bytes Read:      6GB              9MB

Bytes Written:    1MB             587MB   

Total Reduction Ratio: 90.0

Now - I can see this command is run on a WAE where it is the "Server end" of the connection due the large read value on the Original (LAN) side.

BUT why is the optimised read greater than the original write???

I will be eternally grateful to anyone who can explain this to me ....

Regards

[ktunugun]

Hi Ryan,

Let me try to explain you.

1st Scenario

This output looks to be taken from the WAE closer to the client.

Original Bytes Read: This is the client request that is sent to the server to the get the data. This is intercepted by the WAE on the original side (LAN)

Optimized Bytes Read: This is the amount of data that the WAE has received from WAN against the original request.

Original Bytes Written: This is the amount of data that the WAE has sent towards the LAN to the client after decoding and replacing the encoded packets with actual data content.

The Reduction Ratio goes like this (Optimized Read + Optimized Write) / (Original Read + Original Write)

= (1 - (157385 + 4251) / (390 + 246821)) % = 34.616%

Scenario 2

The output is from the Server side WAE.

Original Bytes Read: This is the amount of data that the WAE received from the LAN side (which is server)

Optimized Bytes Written: This is the amount of data that the WAE has sent out on the WAN after performing the encoding process.

Original Bytes Written: This is the acknowldgements that the WAE has sent to the server on LAN.

Optimized Bytes Read: This is the amount the data received by the WAE from the other WAE acknolwdgements and other administrative exchange for this session.

So if we apply the above formula in this case:

= (1 - (9 + 587) / (6000 + 1)) % = 90.202%

Hope this helps.

Regards

Kiran

[ryanoneil1980]

Kiran

Thanks for the reply.

Totally understand and agree the definitions and understand the 2 scenarios.

The two questions I still have are this:

1 - In Scenario 1 how can you explain the 'Optimised Written' value that is greater the 'Original Read' value of greater than a factor of 10 (390 v 4251)??

2 - In Scenario 2 how can you explain that the 'Optimised Read' value is greater than the 'Original Write' value'?? Again this is by quite a margin and nearly 9x as big

My expectation would be that when going from Optimised to original the were would be an increase in traffic & from Original to Optimised a decrease in traffic ...

How can I explain the above numbers? Where can I look? And what should I look for?

Really appreciate your input ....

Ryan