This selects how APS protocol coordination messages are exchanged with the far-end network element for this group -- options typically include in-band methods like the SONET DCC/K-bytes or an out-of-band method like IP -- and setting it specifically to 'ip' has a concrete dependency: the admin must also then configure cApsConfigFarEndIpAddressType, cApsConfigFarEndIpAddress, and cApsConfigFarEndGroupName or the transport won't have a destination to send to. Choosing this setting matters because different transports have different reliability and latency characteristics for exchanging the K1/K2-equivalent protection signaling, which directly affects how quickly a protection switch can be coordinated with the far end. For example, an admin choosing IP transport for APS messaging (perhaps because the SONET overhead bytes aren't available end-to-end) must remember to also fill in the three far-end IP-related objects, or the APS group will have no way to actually reach its peer.