Proper way of implementing a sequential queue

Hi all,

I'm facing my first TB installation for a call center, so I'm dealing with queues for the first time (other than just playing around a bit). My client wants a queue with static agents, where they are called in an ordered way. Let's wonder the following:

We have:

* First line support: Extensions 100, 101, 102
* Second line support: Extensions 200 201 202
* Third line support: Extensions 300 301 302

The client' expected behaviour is to first call 100, then 101, then 102.. if no one answers start with 200, 201 202 -> 300 301 302 and finally send the call to a VM and send message by email.

I've implemented it by creating three queues, with agents:

100,1
101,2
102,3

and the same for queue 2 and 3. Then, Queue1 has Queue2 as failover destination and the same with Queue2 and Queue3. Is this the best way of implementing this? Will it behave properly with load? I'm using TB 2.8.0.4. I've read a lot about the queues problem in TB2.8 series, but I think that I can stay with just "ringall" strategy.

Thanks a lot for your help.

EDIT: I'm asking this because the TB Queue module, in the Static Agents textbox, warns about: "Use penalties at your own risk, they are very broken in asterisk." so I don't know if I should build my queue system aroun penalties.