diff --git a/conf/default_ports.conf b/conf/default_ports.conf
index 7b09c2f..3ac262a 100644
--- a/conf/default_ports.conf
+++ b/conf/default_ports.conf
@@ -208,6 +208,25 @@ standard_webex_udp_ports="9000"
 standard_webex_tcp_fall_back_ports="5004"
 
 
+# - Skype for Business Online und Microsoft Teams
+# -
+# - see: https://docs.microsoft.com/de-de/microsoft-365/enterprise/urls-and-ip-address-ranges?view=o365-worldwide#skype-for-business-online-and-microsoft-teams
+# -
+# -    TCP  80,443
+# -
+# -    UDP  3478,3479,3480,3481   -->  13.107.64.0/18, 52.112.0.0/14, 52.120.0.0/14
+# -
+standard_ms_skype_teams_tcp_ports="80,443"
+standard_ms_skype_teams_udp4_ports="3478,3479,3480,3481"
+standard_ms_skype_teams_udp4_hosts="
+   13.107.64.0/18
+   52.112.0.0/14
+   52.120.0.0/14
+"
+standard_ms_skype_teams_udp6_ports=""
+standard_ms_skype_teams_udp6_hosts=""
+
+
 # - Zoom Meeting - Video Conference Service
 # -
 # -   TCP   80,443         A  ll Zoom Clients and    *.zoom.us
diff --git a/conf/main_ipv4.conf.sample b/conf/main_ipv4.conf.sample
index 1cbe68c..f15230a 100644
--- a/conf/main_ipv4.conf.sample
+++ b/conf/main_ipv4.conf.sample
@@ -920,6 +920,20 @@ bigbluebutton_tcp_ports="$standard_bigbluebutton_tcp_ports"
 bigbluebutton_udp_ports="$standard_bigbluebutton_udp_port_range"
 
 
+# ======
+# - Skype for Business Online und Microsoft Teams
+# ======
+
+# - Skype for Business Online und Microsoft Teams
+# -
+# -    TCP 80,443
+# -
+# -    UDP 3478,3479,3480,3481   -->   13.107.64.0/18, 52.112.0.0/14, 52.120.0.0/14
+# -
+ms_skype_teams_tcp_ports="$standard_ms_skype_teams_tcp_ports"
+ms_skype_teams_udp4_ports="$standard_ms_skype_teams_udp6_ports"
+ms_skype_teams_udp4_hosts="$standard_ms_skype_teams_udp4_hosts"
+
 
 # ======
 # - Webex Meeting
@@ -1550,6 +1564,7 @@ allow_mumble_request_out=true
 allow_outbound_streaming=true
 allow_echo360_video_streaming=true
 allow_bigbluebutton_video_conference_out=true
+allow_ms_skype_teams_out=true
 allow_webex_video_conference_out=true
 allow_zoom_video_conference_out=true
 allow_jitsi_video_conference_out=true
diff --git a/conf/main_ipv6.conf.sample b/conf/main_ipv6.conf.sample
index 422b00f..0554a03 100644
--- a/conf/main_ipv6.conf.sample
+++ b/conf/main_ipv6.conf.sample
@@ -891,6 +891,18 @@ bigbluebutton_tcp_ports="$standard_bigbluebutton_tcp_ports"
 bigbluebutton_udp_ports="$standard_bigbluebutton_udp_port_range"
 
 
+# ======
+# - Skype for Business Online und Microsoft Teams
+# ======
+
+# - Skype for Business Online und Microsoft Teams
+# -
+# -    TCP 80,443
+# -
+ms_skype_teams_tcp_ports="$standard_ms_skype_teams_tcp_ports"
+ms_skype_teams_udp6_ports="$standard_ms_skype_teams_udp6_ports"
+ms_skype_teams_udp6_hosts="$standard_ms_skype_teams_udp6_hosts"
+
 
 # ======
 # - Webex Meeting
@@ -1466,6 +1478,7 @@ allow_outbound_streaming=true
 allow_echo360_video_streaming=true
 allow_alfaview_video_conference_out=true
 allow_bigbluebutton_video_conference_out=true
+allow_ms_skype_teams_out=true
 allow_webex_video_conference_out=true
 allow_zoom_video_conference_out=true
 allow_jitsi_video_conference_out=true
diff --git a/conf/post_decalrations.conf b/conf/post_decalrations.conf
index 0b2226c..b03a8f9 100644
--- a/conf/post_decalrations.conf
+++ b/conf/post_decalrations.conf
@@ -632,7 +632,7 @@ _tmp_tcp_ports="$bigbluebutton_tcp_ports"
 bigbluebutton_tcp_ports=""
 declare -i count=0
 IFS=',' ; for _port in $_tmp_tcp_ports ; do
-   if containsElement "${_port}" "${standard_http_port_arr[@]}" ; then   
+   if $allow_http_request_out && containsElement "${_port}" "${standard_http_port_arr[@]}" ; then   
       continue
    fi
    if [[ $count -eq 0 ]]; then
@@ -645,6 +645,48 @@ done
 IFS="$CUR_IFS"
 
 
+# ---
+# - Skype for Business Online und Microsoft Teams
+# ---
+CUR_IFS="$IFS"
+declare -a ms_skype_teams_udp4_host_arr
+declare -a ms_skype_teams_udp6_host_arr
+declare -a ms_skype_teams_udp4_port_arr
+declare -a ms_skype_teams_udp6_port_arr
+declare -a ms_skype_teams_tcp_port_arr
+if [[ -n "$ms_skype_teams_udp4_hosts" ]]; then
+   for _host in $ms_skype_teams_udp4_hosts ; do
+      ms_skype_teams_udp4_host_arr+=("$_host")
+   done
+fi
+if [[ -n "$ms_skype_teams_udp6_hosts" ]]; then
+   for _host in $ms_skype_teams_udp6_hosts ; do
+      ms_skype_teams_udp6_host_arr+=("$_host")
+   done
+fi
+IFS=',' ; for _port in $ms_skype_teams_udp4_ports ; do
+   if containsElement "${_port}" "${standard_turn_service_port_arr[@]}" ; then
+      continue
+   fi
+   ms_skype_teams_udp_port4_arr+=("$_port")
+done
+IFS="$CUR_IFS"
+IFS=',' ; for _port in $ms_skype_teams_udp6_ports ; do
+   if containsElement "${_port}" "${standard_turn_service_port_arr[@]}" ; then
+      continue
+   fi
+   ms_skype_teams_udp_port6_arr+=("$_port")
+done
+IFS="$CUR_IFS"
+IFS=',' ; for _port in $ms_skype_teams_tcp_ports ; do
+   if $allow_http_request_out && containsElement "${_port}" "${standard_http_port_arr[@]}" ; then
+      continue
+   fi
+   ms_skype_teams_tcp_port_arr+=("$_port")
+done
+IFS="$CUR_IFS"
+
+
 # ---
 # Zoom Meetings - Video Conference - adjust 'zoom_tcp_ports'
 # ---
diff --git a/ip6t-firewall-gateway b/ip6t-firewall-gateway
index 2b1ca90..cd85a26 100755
--- a/ip6t-firewall-gateway
+++ b/ip6t-firewall-gateway
@@ -3120,6 +3120,7 @@ if $allow_outbound_streaming \
    || $allow_echo360_video_streaming \
    || $allow_bigbluebutton_video_conference_out \
    || $allow_webex_video_conference_out \
+   || $allow_ms_skype_teams_out \
    || $allow_zoom_video_conference_out \
    || $allow_jitsi_video_conference_out \
    || $allow_alfaview_video_conference_out \
@@ -3206,6 +3207,52 @@ else
 fi
 
 
+# ---
+# - Skype for Business Online und Microsoft Teams
+# ---
+
+echononl "\t\tSkype for Business Online und Microsoft Teams"
+
+if $allow_ms_skype_teams_out \
+      && ( [[ ${#ms_skype_teams_udp6_host_arr[@]} -gt 0 ]] && [[ ${#ms_skype_teams_udp_port_arr[@]} -gt 0 ]] ) \
+      || [[ ${#ms_skype_teams_tcp_port_arr[@]} -gt 0 ]] ; then
+
+   for _dev in ${ext_if_arr[@]} ; do
+
+      if [[ ${#ms_skype_teams_udp6_host_arr[@]} -gt 0 ]] && [[ ${#ms_skype_teams_udp_port_arr[@]} -gt 0 ]] ; then
+
+         for _host in ${ms_skype_teams_udp6_host_arr[@]} ; do
+
+            for _port in ${ms_skype_teams_udp_port_arr[@]} ; do
+
+               $ip6t -A OUTPUT -o $_dev -p udp -d $_host -dport $_port -m conntrack --ctstate NEW -j ACCEPT
+               if $kernel_forward_between_interfaces && ! $permit_local_net_to_inet ; then
+                  $ip6t -A FORWARD -o $_dev -p udp -d $_host -dport $_port -m conntrack --ctstate NEW -j ACCEPT
+               fi
+            done
+
+         done
+      fi
+
+      if [[ ${#ms_skype_teams_tcp_port_arr[@]} -gt 0 ]] ; then
+
+         for _port in ${ms_skype_teams_tcp_port_arr[@]} ; do
+
+            $ip6t -A OUTPUT -o $_dev -p udp -d $_host -dport $_port -m conntrack --ctstate NEW -j ACCEPT
+            if $kernel_forward_between_interfaces && ! $permit_local_net_to_inet ; then
+               $ip6t -A FORWARD -o $_dev -p udp -d $_host -dport $_port -m conntrack --ctstate NEW -j ACCEPT
+            fi
+         done
+
+      fi
+
+   done # for _dev in ${ext_if_arr[@]} ; do
+   echo_done
+else
+   echo_skipped
+fi
+
+
 # ---
 # - Webex Meeting Video Conference Service out only
 # ---
diff --git a/ipt-firewall-gateway b/ipt-firewall-gateway
index 47f75e1..540f47a 100755
--- a/ipt-firewall-gateway
+++ b/ipt-firewall-gateway
@@ -3873,6 +3873,7 @@ echononl "\t\tTurn/Stun Service"
 if $allow_outbound_streaming \
    || $allow_echo360_video_streaming \
    || $allow_bigbluebutton_video_conference_out \
+   || $allow_ms_skype_teams_out \
    || $allow_webex_video_conference_out \
    || $allow_zoom_video_conference_out \
    || $allow_jitsi_video_conference_out \
@@ -3959,6 +3960,52 @@ else
 fi
 
 
+# ---
+# - Skype for Business Online und Microsoft Teams
+# ---
+
+echononl "\t\tSkype for Business Online und Microsoft Teams"
+
+if $allow_ms_skype_teams_out \
+      && ( [[ ${#ms_skype_teams_udp4_host_arr[@]} -gt 0 ]] && [[ ${#ms_skype_teams_udp_port_arr[@]} -gt 0 ]] ) \
+      || [[ ${#ms_skype_teams_tcp_port_arr[@]} -gt 0 ]]) ; then
+
+   for _dev in ${ext_if_arr[@]} ; do
+
+      if [[ ${#ms_skype_teams_udp4_host_arr[@]} -gt 0 ]] && [[ ${#ms_skype_teams_udp_port_arr[@]} -gt 0 ]] ; then
+
+         for _host in ${ms_skype_teams_udp4_host_arr[@]} ; do
+
+            for _port in ${ms_skype_teams_udp_port_arr[@]} ; do
+
+               $ipt -A OUTPUT -o $_dev -p udp -d $_host -dport $_port -m conntrack --ctstate NEW -j ACCEPT
+               if $kernel_activate_forwarding && ! $permit_local_net_to_inet ; then
+                  $ipt -A FORWARD -o $_dev -p udp -d $_host -dport $_port -m conntrack --ctstate NEW -j ACCEPT
+               fi
+            done
+
+         done
+      fi
+
+      if [[ ${#ms_skype_teams_tcp_port_arr[@]} -gt 0 ]] ; then
+
+         for _port in ${ms_skype_teams_tcp_port_arr[@]} ; do
+
+            $ipt -A OUTPUT -o $_dev -p udp -d $_host -dport $_port -m conntrack --ctstate NEW -j ACCEPT
+            if $kernel_activate_forwarding && ! $permit_local_net_to_inet ; then
+               $ipt -A FORWARD -o $_dev -p udp -d $_host -dport $_port -m conntrack --ctstate NEW -j ACCEPT
+            fi
+         done
+
+      fi
+
+   done # for _dev in ${ext_if_arr[@]} ; do
+   echo_done
+else
+   echo_skipped
+fi
+
+
 # ---
 # - Webex Meeting Video Conference Service out only
 # ---