Firewall Ranges for ACD VOIP
From WIKI - ACD.net
ACD's VOIP switched network needs to be able to communicate to your voip. Typically customers should allow access from these IP addresses, and should allow ICMP, SIP (port 5060, and 5061) as well as all RTP traffic.
- 220.127.116.11/27 - ACD VOIP Switched Network