diff --git a/check_iperf3.sh b/check_iperf3.sh
index 4037de5..0ed6eb0 100755
--- a/check_iperf3.sh
+++ b/check_iperf3.sh
@@ -1,102 +1,87 @@
 #!/usr/bin/env bash
 
-function print_help {
-  echo "Usage: $0 --server SERVER --warning WARNING --critical CRITICAL --rsa-key RSA_KEY --username USERNAME --password PASSWORD"
-  echo ""
-  echo "Arguments:"
-  echo "  --server   The iperf3 server to test against"
-  echo "  --warning  Warning level for the speed test in Mbits/s"
-  echo "  --critical Critical level for the speed test in Mbits/s"
-  echo "  --rsa-key  Path to the RSA public key for authentication"
-  echo "  --username Username for authentication"
-  echo "  --password Password for authentication"
-  echo ""
-  exit 3
-}
-
-if ! command -v iperf3 &>/dev/null; then
-  echo "UNKNOWN - iperf3 is not installed"
-  exit 3
-fi
-
-if ! command -v jq &>/dev/null; then
-  echo "UNKNOWN - jq is not installed"
-  exit 3
-fi
-
-if [[ $# -eq 0 ]]; then
-  print_help
-fi
+# Default values
+SERVER=""
+WARNING_LEVEL=""
+CRITICAL_LEVEL=""
+RSA_PUBLIC_KEY=""
+USERNAME=""
+PASSWORD=""
 
+# Parse named arguments
 while [[ $# -gt 0 ]]; do
   key="$1"
 
   case $key in
-  --server)
-    SERVER="$2"
-    shift
-    shift
-    ;;
-  --warning)
-    WARNING="$2"
-    shift
-    shift
-    ;;
-  --critical)
-    CRITICAL="$2"
-    shift
-    shift
-    ;;
-  --rsa-key)
-    RSA_KEY="$2"
-    shift
-    shift
-    ;;
-  --username)
-    USERNAME="$2"
-    shift
-    shift
-    ;;
-  --password)
-    PASSWORD="$2"
-    shift
-    shift
-    ;;
-  *)
-    print_help
-    ;;
+    --server)
+      SERVER="$2"
+      shift
+      shift
+      ;;
+    --warning)
+      WARNING_LEVEL="$2"
+      shift
+      shift
+      ;;
+    --critical)
+      CRITICAL_LEVEL="$2"
+      shift
+      shift
+      ;;
+    --rsa-public-key)
+      RSA_PUBLIC_KEY="$2"
+      shift
+      shift
+      ;;
+    --username)
+      USERNAME="$2"
+      shift
+      shift
+      ;;
+    --password)
+      PASSWORD="$2"
+      shift
+      shift
+      ;;
+    *)
+      shift
+      ;;
   esac
 done
 
-if [[ -z "$SERVER" ]] || [[ -z "$WARNING" ]] || [[ -z "$CRITICAL" ]] || [[ -z "$RSA_KEY" ]] || [[ -z "$USERNAME" ]] || [[ -z "$PASSWORD" ]]; then
-  echo "UNKNOWN - All arguments are required"
-  print_help
+# Check if required arguments are provided
+if [[ -z "$SERVER" ]] || [[ -z "$WARNING_LEVEL" ]] || [[ -z "$CRITICAL_LEVEL" ]]; then
+  echo "Usage: $0 --server SERVER --warning WARNING_LEVEL --critical CRITICAL_LEVEL [--rsa-public-key RSA_PUBLIC_KEY] [--username USERNAME] [--password PASSWORD]"
+  exit -1
 fi
 
+# Set IPERF3_PASSWORD environment variable
 export IPERF3_PASSWORD="$PASSWORD"
 
-RESULT=$(iperf3 -c $SERVER -u -b 0 -J -t 10 --rsa-public-key-path $RSA_KEY --username $USERNAME 2>&1)
+# Run iperf3 command with optional arguments
+if [[ -n "$RSA_PUBLIC_KEY" ]] && [[ -n "$USERNAME" ]]; then
+  OUTPUT=$(iperf3 -c "$SERVER" -i 1 -t 10 -f m --rsa-public-key-path "$RSA_PUBLIC_KEY" --username "$USERNAME" 2>&1)
+else
+  OUTPUT=$(iperf3 -c "$SERVER" -i 1 -t 10 -f m 2>&1)
+fi
+
+# Check if iperf3 command failed
 if [[ $? -ne 0 ]]; then
-  echo "UNKNOWN - iperf3 command failed: $RESULT"
-  exit 3
+  echo "UNKNOWN - iperf3 command failed: $OUTPUT"
+  exit -1
 fi
 
-if ! echo "$RESULT" | jq -e '.end.sum.bits_per_second' >/dev/null; then
-  echo "UNKNOWN - Invalid JSON output from iperf3: $RESULT"
-  exit 3
-fi
+# Extract the receiver bitrate
+RECEIVER_BITRATE=$(echo "$OUTPUT" | grep -Eo '[0-9]+(\.[0-9]+)? Mbits/sec' | tail -1 | awk '{print $1}')
 
-STREAM_RESULT=$(echo "$RESULT" | jq '.end.streams[] | select(.udp.sender == (!0)) | .udp.bits_per_second')
-SPEED_RAW=$(echo "$STREAM_RESULT" | jq 'if length > 0 then . / 1000000 else 0 end')
-SPEED=$(printf "%.0f" "$SPEED_RAW")
-
-if (($(echo "$SPEED < $CRITICAL" | bc -l))); then
-  echo "CRITICAL - Speed: ${SPEED} Mbits/s"
+# Check the receiver bitrate against warning and critical levels
+if (( $(echo "$RECEIVER_BITRATE < $CRITICAL_LEVEL" | bc -l) )); then
+  echo "CRITICAL - Receiver Bitrate: $RECEIVER_BITRATE Mbits/sec"
   exit 2
-elif (($(echo "$SPEED < $WARNING" | bc -l))); then
-  echo "WARNING - Speed: ${SPEED} Mbits/s"
+elif (( $(echo "$RECEIVER_BITRATE < $WARNING_LEVEL" | bc -l) )); then
+  echo "WARNING - Receiver Bitrate: $RECEIVER_BITRATE Mbits/sec"
   exit 1
 else
-  echo "OK - Speed: ${SPEED} Mbits/s"
+  echo "OK - Receiver Bitrate: $RECEIVER_BITRATE Mbits/sec"
   exit 0
 fi