1) Welcome to the Party!
2) As you are obviously new here, I have some suggestions to help us all help you:
When you post, please post your entire configuration including (but not limited to) your installation method and vicidial version with build.
This IS a requirement for posting along with reading the stickies (at the top of each forum) and the manager's manual (available on EFLO.net, both free and paid versions)
You should also post: Asterisk version, telephony hardware (model number is helpful here), cluster information if you have one, and whether any other software is installed in the box. If your installation method is "from scratch" you must post your operating system and should also post the .iso version from which you installed your original operating system. If your installation is "Hosted" list the site name of the host.
If this is a "Cloud" or "Virtual" server, please note the technology involved along with the version of that techology (ie: VMware Server Version 2.0.2). If it is not, merely stating the Motherboard model # and CPU would be helpful.
Similar to This:
Vicibox X.X from .iso | Vicidial X.X.X-XXX Build XXXXXX-XXXX | Asterisk X.X.X | Single Server | No Digium/Sangoma Hardware | No Extra Software After Installation | Intel DG35EC | Core2Quad Q6600
3) This is a fairly standard Asterisk response generated when "qualify" is set (to a number or Yes). Qualify causes a timed check on the account. Failure to respond (or response outside the configured value, default of 1 second or "1000" which is also qualify=1000 or qualify=yes, same thing) will result in "auto-congesting". Essentially this means the account is Disqualified from connecting. Asterisk will simply refuse to attempt the connection on this account once qualify has failed (until the next successful qualify packet).
4) Can happen because of dropped packets due to network failure or firewall interference or simply because of poor connection quality (too long to reply). qualify=no removes the error message, but not any underlying failure (ie: if it is merely slow, you may be able to make a poor quality call with qualify=no, but if there is a firewall blocking packets ... qualify=no will simply result in an attempted/failed call instead of auto-congestion blocking the call).
5) Qualify=1000 is designed to allow multiple carriers and a "threshold" below which individual carriers are disqualified so other carriers can accept the traffic with more suitable connections. If you only have ONE carrier, this is not quite so useful. LOL
Happy Hunting!