[VoiceOps] network jitter tools

Peter Childs pchilds at internode.com.au
Tue Aug 25 21:32:43 EDT 2009

That sounds sweet!  I'd love to see/hear how you go from gulping  
chunks of data to finding and extracting what you want from all those  
streams (?)

I hacked up a signalling only fault finding solution based on jNetPcap  
and the H2 in memory database so we capture and store all the  
signalling traffic on the front end of our SBCs... I can store about  
7-8 million packets in about 15GB of RAM, which gives us a few hours  
of back history.

Given some spare CPU cycles on the capture box we can also track and  
monitor things like registration continuity on clients, User-Agent  
make/model/version, and ASNum/CountryCode distribution of clients etc.

On top of that we run a RESTlet server that allows our customer reps  
to run traces on customers via SQL on the in memory database.... the  
resultant data is converted via JavaScript into SVG ladder-trace  

In terms of the original query about network jitter I would assume  
running something like Cisco's IP-SLA or similar between the hop-on/ 
hop-off points of your network would give you some demonstrated  
confidence and assurance in the performance of your own network.

Passive taps will only give you 'partial' view of performance, unless  
both ends support RTCP in which case life is much better.


On 25/08/2009, at 2:42 AM, Jason Vanick wrote:

> +1 on wireshark/packet tracing
> I actually wrote a 'interface' around gulp (a packet grabber) and  
> pcapmerge
> to allow our support folk to selectivly pull traces from a bunch of  
> passive
> taps in our network.
> Initially I was also capturing RTP streams, however, due to legal  
> concerns, I
> now only turn up individual filters for RTP.
> however, all signalling still does get caught.. makes it really easy  
> to retroactively
> look for a packet trace when the customer calls in an hour later  
> with an issue.
> it all currently writes to a 16 TB dedicated EMC SAN.
> I'm getting ready to release my package as open source...   
> internally I call it the
> 'MegaSniffer'... however, not really sure what to name it going  
> forward.
> there's been lots of ideas for go-forward development, including  
> auto-parsing the signalling
> data (sip ladder diagrams, etc)... however, the way it is right now  
> has been used extensively
> by our support folk.
> -J
>> Carlos Alcantar wrote:
>>> Hey guys just putting a list together of tools to diagnose network
>>> jitter what are you guys using out there?
>> Wireshark.

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