diff --git a/README.md b/README.md
index 3d14ed0..1f06c3d 100644
--- a/README.md
+++ b/README.md
@@ -114,6 +114,8 @@ Variable | Description | Example
 `JIGASI_SIP_URI` | SIP URI for incoming / outgoing calls | test@sip2sip.info
 `JIGASI_SIP_PASSWORD` | Password for the specified SIP account | passw0rd
 `JIGASI_SIP_SERVER` | SIP server (use the SIP account domain if in doubt) | sip2sip.info
+`JIGASI_SIP_PORT` | SIP server port | 5060
+`JIGASI_SIP_TRANSPORT` | SIP transport | UDP
 
 ### Authentication
 
diff --git a/env.example b/env.example
index 632adb1..5d9be57 100644
--- a/env.example
+++ b/env.example
@@ -40,12 +40,17 @@ TZ=Europe/Amsterdam
 # SIP URI for incoming / outgoing calls.
 #JIGASI_SIP_URI=test@sip2sip.info
 
-# Password for the specified SIP account.
+# Password for the specified SIP account as a clear text
 #JIGASI_SIP_PASSWORD=passw0rd
 
 # SIP server (use the SIP account domain if in doubt).
 #JIGASI_SIP_SERVER=sip2sip.info
 
+# SIP server port
+#JIGASI_SIP_PORT=5060
+
+# SIP server transport
+#JIGASI_SIP_TRANSPORT=UDP
 
 #
 # Authentication configuration (see README for details)
diff --git a/jigasi.yml b/jigasi.yml
index 5a96062..abdd7a8 100644
--- a/jigasi.yml
+++ b/jigasi.yml
@@ -17,6 +17,8 @@ services:
             - JIGASI_SIP_URI
             - JIGASI_SIP_PASSWORD
             - JIGASI_SIP_SERVER
+            - JIGASI_SIP_PORT
+            - JIGASI_SIP_TRANSPORT
             - JIGASI_XMPP_USER
             - JIGASI_XMPP_PASSWORD
             - JIGASI_BREWERY_MUC
diff --git a/jigasi/rootfs/defaults/sip-communicator.properties b/jigasi/rootfs/defaults/sip-communicator.properties
index 1f04d8d..bc2429a 100644
--- a/jigasi/rootfs/defaults/sip-communicator.properties
+++ b/jigasi/rootfs/defaults/sip-communicator.properties
@@ -8,6 +8,10 @@ net.java.sip.communicator.packetlogging.PACKET_LOGGING_ENABLED=false
 
 # SIP account
 net.java.sip.communicator.impl.protocol.sip.acc1=acc1
+net.java.sip.communicator.impl.protocol.sip.acc1.PROXY_ADDRESS={{ .Env.JIGASI_SIP_SERVER }}
+net.java.sip.communicator.impl.protocol.sip.acc1.PROXY_AUTO_CONFIG=false
+net.java.sip.communicator.impl.protocol.sip.acc1.PROXY_PORT={{ .Env.JIGASI_SIP_PORT }}
+net.java.sip.communicator.impl.protocol.sip.acc1.PREFERRED_TRANSPORT={{ .Env.JIGASI_SIP_TRANSPORT }}
 net.java.sip.communicator.impl.protocol.sip.acc1.ACCOUNT_UID=SIP\:{{ .Env.JIGASI_SIP_URI }}
 net.java.sip.communicator.impl.protocol.sip.acc1.PASSWORD={{ .Env.JIGASI_SIP_PASSWORD | b64enc }}
 net.java.sip.communicator.impl.protocol.sip.acc1.PROTOCOL_NAME=SIP