diff --git a/src/PrefsWrapper.scala b/src/PrefsWrapper.scala
index 08af43d..1be9d4c 100644
--- a/src/PrefsWrapper.scala
+++ b/src/PrefsWrapper.scala
@@ -70,12 +70,12 @@ class PrefsWrapper(val context : Context) {
 			R.array.p_locsource_ev, R.array.p_locsource_e)
 	}
 	def getBackendName() = {
-		val proto = getListItemName("proto", AprsBackend.DEFAULT_CONNTYPE,
+		val proto = getListItemName("proto", AprsBackend.DEFAULT_PROTO,
 			R.array.p_conntype_ev, R.array.p_conntype_e)
 		val link = AprsBackend.defaultProtoInfo(this).link
 		link match {
-		case "aprsis" => "%s, %s".format(proto, getListItemName(link, "tcp", R.array.p_aprsis_ev, R.array.p_aprsis_e))
-		case "link" => "%s, %s".format(proto, getListItemName(link, "tcp", R.array.p_link_ev, R.array.p_link_e))
+		case "aprsis" => "%s, %s".format(proto, getListItemName(link, AprsBackend.DEFAULT_CONNTYPE, R.array.p_aprsis_ev, R.array.p_aprsis_e))
+		case "link" => "%s, %s".format(proto, getListItemName(link, AprsBackend.DEFAULT_CONNTYPE, R.array.p_link_ev, R.array.p_link_e))
 		case _ => proto
 		}
 	}
diff --git a/src/backend/AprsBackend.scala b/src/backend/AprsBackend.scala
index 4951e7b..70ca64c 100644
--- a/src/backend/AprsBackend.scala
+++ b/src/backend/AprsBackend.scala
@@ -5,7 +5,15 @@ import _root_.net.ab0oo.aprs.parser.APRSPacket
 import _root_.java.io.{InputStream, OutputStream}
 
 object AprsBackend {
+        /** "Modular" system to connect to an APRS backend.
+        * The backend config consists of three items backed by prefs values:
+        *   - *proto* inside the connection ("aprsis", "afsk", "kiss", "tnc2", "kenwood") - ProtoInfo class
+        *   - *link* type ("bluetooth", "usb", "tcpip"; only for "kiss", "tnc2", "kenwood") - BackendInfo class
+        *   - *aprsis* mode ("tcp", "http", "udp"; only for proto=aprsis) - BackendInfo class
+        */
 	val DEFAULT_CONNTYPE = "tcp"
+	val DEFAULT_LINK = "tcpip"
+	val DEFAULT_PROTO = "aprsis"
 
 	val PASSCODE_NONE	= 0
 	val PASSCODE_OPTIONAL	= 1
@@ -26,9 +34,9 @@ object AprsBackend {
 
 	// map from old "backend" to new proto-link-aprsis (defaults are bluetooth and tcp)
 	val backend_upgrade = Map(
-		"tcp" -> "aprsis-bluetooth-tcp",
-		"udp" -> "aprsis-bluetooth-udp",
-		"http" -> "aprsis-bluetooth-http",
+		"tcp" -> "aprsis-tcpip-tcp",
+		"udp" -> "aprsis-tcpip-udp",
+		"http" -> "aprsis-tcpip-http",
 		"afsk" -> "afsk-bluetooth-tcp",
 		"bluetooth" -> "kiss-bluetooth-tcp",
 		"kenwood" -> "kenwood-bluetooth-tcp",
@@ -115,7 +123,7 @@ object AprsBackend {
 
 	def defaultBackendInfo(prefs : PrefsWrapper) : BackendInfo = {
 		val pi = defaultProtoInfo(prefs)
-		val link = if (pi.link != null) { prefs.getString(pi.link, "bluetooth") } else { prefs.getProto() }
+		val link = if (pi.link != null) { prefs.getString(pi.link, DEFAULT_LINK) } else { prefs.getProto() }
 		backend_collection.get(link) match {
 		case Some(bi) => bi
 		case None => backend_collection(DEFAULT_CONNTYPE)