In a parallel hunt group, calls simultaneously ring multiple phones. In versions earlier than Cisco Unified CME 4.3, only SIP
phones support parallel hunt groups. In Cisco Unified CME 4.3 and later versions, SCCP phones also support voice hunt groups.
http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/admin/configuration/guide/cmecover.html#wp1145800
In the following parallel hunt group example, when callers dial extension 1000, extension 1001, 1002, and so on ring
simultaneously. The first extension to answer is connected. If none of the extensions answers, the call is forwarded to
extension 2000, which is the number for the voice-mail service.
voice hunt-group 4 parallel
pilot 1000
list 1001, 1002, 1003, 1004
final 2000
timeout 20
Prior to CME 4.3, you can enable functionality similar to parallel hunt groups on SCCP phones by using the ephone-dn overlay
feature for shared lines.
http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/admin/configuration/guide/cmecover.html#wp1148195
