[Mikrotik]
http://www.mikrotik.com
http://wiki.mikrotik.com
http://forum.mikrotik.com

[FreeBSD]
http://www.freebsd.org
http://www.freebsd.org/handbook
http://www.fug.com.br

[Cisco]
http://www.cisco.com
http://www.imasters.com.br

[Asterisk]
http://www.asterisk.com
http://www.trixbox.com
http://www.asteriskexperts.com.br
http://dumbme.voipeye.com.au/trixbox/trixbox_without_tears.htm

[Outros]
http://under-linux.org/forums
http://www.visolve.com/squid/squid26/contents.php
http://www.laserwifi.com/watts-dbm.htm

[Fornecedores]
http://www.lojacisco.com.br
http://www.shopvoip.com.br