rand0muid

Well, its approach (quoting its project page) is pretty simple:

Echofish is a purpose-built solution for filtering & monitoring of syslog activity. By whitelisting regular messages through the web UI, the administrator can instruct the log processing mechanism to create alerts only for anomalies (irregular messages).

...and actually, it can do lots more once you read the built-in help (such as distribution (using BGP) of IP blacklists, consisting of IP addresses collected through syslog activity).

TLDR; It's gearred towards filtering noise from logs. This also means you can possibly have another daemon reporting network activity through syslog, while echofish can act as your noise-filter.

You should give Echofish atry. It's made wonders on our network with its "whitelisting of normal behaviour". You wont beleive the things you ll discover with this approach.

EDIT: The most fascinating aspect for me is that echofish is more geared towards the actual log entries, rather than statistical analysis, in order to automatically detect anomalies in your logs activity.