Howdy,
something we have been missing in the Lync Community is a place, one place that contain the information & skills you need to know and have to troubleshoot technical problem with Lync (Skype for Business)
well it is finally here, all credits and thanks to Thomas Poett (Author and Lync MVP). He was working on this “FREE” guide for a while and we (I know I was) waiting for this guide to be released which it was today.
in this guide Thomas started with the basics that administrator and/or Support engineer need to have to help troubleshooting problems with Lync, then he took it more deeper into how to conduct the troubleshooting.
The guide addressed a big variety of subjects some of I really enjoyed
- TCP and SIP Protocol
- SIP Session Establishment
- Diagnostic Header
and many more interesting subjects are inside the guide, you can learn more about it in Thomas Article in his Blog (LyncUC)
And you can (and should) download the guide from here 
enjoy it and don’t forget to thank Mr. Poett
February 5, 2015 at 6:26 am
Can I say your posts have been invaluable whilst rolling out Lync at our non-profit organisation. As a first timer with Lync it’s been quite the learning curve, however I’ve managed to work through all issues thus far bar the following.
I’ve setup Lync/Skype federation and can add contacts, send IM’s and see presence. However making calls seems to be only possible if both participants are on our local network. For example I’ve setup two laptops on our internal network with one signed into Lync and the other into Skype, calls between them work fine. However when I put the Skype laptop onto an external network when accepting the call it drops instantly stating “Networking issue”
Externally Lync to Lync works perfect it just seems to be Lync to Skype which doesn’t and I’m lost how to troubleshoot it.
Thankyou for taking a moment to read this, any advice you can offer would be most appreciated.
February 13, 2015 at 9:08 am
Hi Adam,
Thank you so much for your kind words, and i’m glad i managed to help you.
did you try to capture the SIP Stack logs on the Edge server as well as the Client while trying the call ?