diff --git a/.github/docker/Dockerfile.ssut b/.github/docker/Dockerfile.ssut
new file mode 100644
index 0000000..cc40367
--- /dev/null
+++ b/.github/docker/Dockerfile.ssut
@@ -0,0 +1,21 @@
+# syntax=docker/dockerfile:1
+
+ARG BASE_IMAGE=ghcr.io/sippy/rtpproxy:latest
+FROM ${BASE_IMAGE}
+
+ARG MM_TYPE
+ARG MM_BRANCH
+
+ENV MM_TYPE=${MM_TYPE} \
+    MM_BRANCH=${MM_BRANCH} \
+    RTPP_BRANCH=DOCKER \
+    BASEDIR=/opt/voiptests \
+    BUILDDIR=/opt/voiptests \
+    PYTHON_CMD=python3 \
+    DEBIAN_FRONTEND=noninteractive
+
+WORKDIR /opt/voiptests
+
+COPY . /opt/voiptests
+
+RUN /bin/sh -eux ./cibits/build_ssut_image.sh
diff --git a/.github/workflows/.main.yml b/.github/workflows/.main.yml
index e3c8ea9..a0c5fd5 100644
--- a/.github/workflows/.main.yml
+++ b/.github/workflows/.main.yml
@@ -3,10 +3,6 @@ name: Reusable Workflow
 on:
   workflow_call:
     inputs:
-      python-version:
-        required: false
-        type: string
-        default: '3.12'
       mm-type:
         required: true
         type: string
@@ -14,13 +10,21 @@ on:
         required: false
         type: string
         default: 'master'
-      mm-auth:
+      mm-auths:
         required: false
         type: string
-        default: ''
-      rtppc-type:
+        default: '[""]'
+      python-versions:
+        required: false
+        type: string
+        default: '["3.12"]'
+      rtppc-types:
         required: true
         type: string
+      use-local-image:
+        required: false
+        type: boolean
+        default: false
       rtpp-image:
         required: false
         type: string
@@ -35,63 +39,246 @@ on:
         default: ''
 
 jobs:
-  test:
+  build_ssut_image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    outputs:
+      image-ref: ${{ steps.meta.outputs.image-ref }}
+      image-artifact: ${{ steps.meta.outputs.image-artifact }}
+    env:
+      DOCKER_BUILD_SUMMARY: false
+      DOCKER_BUILD_RECORD_UPLOAD: false
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Compute image metadata
+        id: meta
+        run: |
+          MM_BRANCH_SAFE="$(echo '${{ inputs.mm-branch }}' | sed 's|[^a-zA-Z0-9_.-]|-|g')"
+          SHA_SHORT="$(printf '%s' "$GITHUB_SHA" | cut -c1-12)"
+          IMAGE_REF="ghcr.io/${{ github.repository_owner }}/voiptests-${{ inputs.mm-type }}:ssut-${MM_BRANCH_SAFE}-${SHA_SHORT}"
+          IMAGE_ARTIFACT="ssut-image-${{ inputs.mm-type }}-${MM_BRANCH_SAFE}-${GITHUB_RUN_ID}-${GITHUB_RUN_ATTEMPT}"
+          echo "image-ref=${IMAGE_REF}" >> "$GITHUB_OUTPUT"
+          echo "image-artifact=${IMAGE_ARTIFACT}" >> "$GITHUB_OUTPUT"
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to GHCR
+        if: ${{ !inputs.use-local-image }}
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push SSUT image
+        if: ${{ !inputs.use-local-image }}
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./.github/docker/Dockerfile.ssut
+          push: true
+          tags: ${{ steps.meta.outputs.image-ref }}
+          build-args: |
+            BASE_IMAGE=${{ inputs.rtpp-image }}:${{ inputs.rtpp-image-tag }}
+            MM_TYPE=${{ inputs.mm-type }}
+            MM_BRANCH=${{ inputs.mm-branch }}
+
+      - name: Build SSUT image tarball
+        if: ${{ inputs.use-local-image }}
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./.github/docker/Dockerfile.ssut
+          outputs: type=docker,dest=/tmp/ssut-image.tar
+          tags: ${{ steps.meta.outputs.image-ref }}
+          build-args: |
+            BASE_IMAGE=${{ inputs.rtpp-image }}:${{ inputs.rtpp-image-tag }}
+            MM_TYPE=${{ inputs.mm-type }}
+            MM_BRANCH=${{ inputs.mm-branch }}
+
+      - name: Upload SSUT image artifact
+        if: ${{ inputs.use-local-image }}
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ steps.meta.outputs.image-artifact }}
+          path: /tmp/ssut-image.tar
+
+  test_ghcr:
+    if: ${{ !inputs.use-local-image }}
     runs-on: ubuntu-latest
+    needs: [build_ssut_image]
     container:
-      image: ${{ inputs.rtpp-image }}:${{ inputs.rtpp-image-tag }}
+      image: ${{ needs.build_ssut_image.outputs.image-ref }}
       options: --privileged --sysctl net.ipv6.conf.all.disable_ipv6=0
     env:
       MM_TYPE: ${{ inputs.mm-type }}
       MM_BRANCH: ${{ inputs.mm-branch }}
       RTPP_BRANCH: DOCKER
-      RTPPC_TYPE: ${{ inputs.rtppc-type }}
+      RTPPC_TYPE: ${{ matrix.rtppc-type }}
+      MM_AUTH: ${{ matrix.mm-auth }}
+      ARTIFACT_FILES: ${{ inputs.artifact-files }}
+    strategy:
+      fail-fast: false
+      matrix:
+        rtppc-type: ${{ fromJSON(inputs.rtppc-types) }}
+        mm-auth: ${{ fromJSON(inputs.mm-auths) }}
+        python-version: ${{ fromJSON(inputs.python-versions) }}
     steps:
-      - uses: actions/checkout@v4
-
-      - name: Set up Python ${{ inputs.python-version }}
+      - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:
-          python-version: ${{ inputs.python-version }}
+          python-version: ${{ matrix.python-version }}
 
       - name: Define PYTHON_CMD
-        run: |
-          PYTHON_VER="`echo ${{ matrix.python-version }} | sed 's|-dev$||'`"
-          echo "PYTHON_CMD=python${PYTHON_VER}" >> $GITHUB_ENV
+        run: echo "PYTHON_CMD=${pythonLocation}/bin/python" >> "$GITHUB_ENV"
 
-      - name: before_install
-        run: sh -x cibits/before_install.sh
+      - name: Install Python dependencies
+        run: |
+          cd /opt/voiptests
+          ${PYTHON_CMD} -m pip install --upgrade pip
+          ${PYTHON_CMD} -m pip install -r requirements.txt
+          if [ "${MM_TYPE}" = "b2bua" ]
+          then
+            ${PYTHON_CMD} -m pip install -U -r dist/b2bua/requirements.txt
+          fi
 
-      - name: transform_var
-        id: transform_var
+      - name: Build artifact name
+        id: artifact_name
         run: |
-          ARTNAME="test-logs_${{ inputs.mm-type }}_${{ inputs.mm-branch }}_${{ inputs.rtppc-type }}"
-          MM_AUTH="`echo "${{ inputs.mm-auth }}" | sed 's|/|.|g'`"
-          if [ "${MM_AUTH}" != "" ]
+          ARTNAME="test-logs_${{ inputs.mm-type }}_${{ inputs.mm-branch }}_${{ matrix.rtppc-type }}"
+          MM_AUTH_SAFE="$(echo "${{ matrix.mm-auth }}" | sed 's|/|.|g')"
+          if [ -n "${MM_AUTH_SAFE}" ]
           then
-            ARTNAME="${ARTNAME}_${MM_AUTH}"
-            echo "MM_AUTH=${{ inputs.mm-auth }}" >> $GITHUB_ENV
+            ARTNAME="${ARTNAME}_${MM_AUTH_SAFE}"
           fi
           if [ "${{ inputs.mm-type }}" = "b2bua" ]
           then
-            ARTNAME="${ARTNAME}_${{ inputs.python-version }}"
+            ARTNAME="${ARTNAME}_${{ matrix.python-version }}"
           fi
-          echo "ARTNAME=${ARTNAME}" >> $GITHUB_OUTPUT
+          echo "artname=${ARTNAME}" >> "$GITHUB_OUTPUT"
 
-      - name: Test (debug)
+      - name: Run tests
         run: |
+          cd /opt/voiptests
+          rm -rf test.logs
+          LOG_FILES="bob.log alice.log rtpproxy.log"
+          if [ -n "${ARTIFACT_FILES}" ]
+          then
+            LOG_FILES="${LOG_FILES} ${ARTIFACT_FILES}"
+          fi
+
           RTPP_VERSION=debug sh -x ./test_run.sh
           mkdir -p test.logs/debug
-          mv bob.log alice.log rtpproxy.log ${{ inputs.artifact-files }} test.logs/debug
+          mv ${LOG_FILES} test.logs/debug
 
-      - name: Test (production)
-        run: |
           RTPP_VERSION=production sh -x ./test_run.sh
           mkdir -p test.logs/production
-          mv bob.log alice.log rtpproxy.log ${{ inputs.artifact-files }} test.logs/production
+          mv ${LOG_FILES} test.logs/production
+
+      - name: Upload test logs
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ steps.artifact_name.outputs.artname }}
+          path: /opt/voiptests/test.logs
+        continue-on-error: true
+
+  test_local:
+    if: ${{ inputs.use-local-image }}
+    runs-on: ubuntu-latest
+    needs: [build_ssut_image]
+    strategy:
+      fail-fast: false
+      matrix:
+        rtppc-type: ${{ fromJSON(inputs.rtppc-types) }}
+        mm-auth: ${{ fromJSON(inputs.mm-auths) }}
+        python-version: ${{ fromJSON(inputs.python-versions) }}
+    steps:
+      - name: Download SSUT image artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ needs.build_ssut_image.outputs.image-artifact }}
+          path: /tmp
+
+      - name: Load SSUT image
+        run: docker load --input /tmp/ssut-image.tar
+
+      - name: Build artifact name
+        id: artifact_name
+        run: |
+          ARTNAME="test-logs_${{ inputs.mm-type }}_${{ inputs.mm-branch }}_${{ matrix.rtppc-type }}"
+          MM_AUTH_SAFE="$(echo "${{ matrix.mm-auth }}" | sed 's|/|.|g')"
+          if [ -n "${MM_AUTH_SAFE}" ]
+          then
+            ARTNAME="${ARTNAME}_${MM_AUTH_SAFE}"
+          fi
+          if [ "${{ inputs.mm-type }}" = "b2bua" ]
+          then
+            ARTNAME="${ARTNAME}_${{ matrix.python-version }}"
+          fi
+          echo "artname=${ARTNAME}" >> "$GITHUB_OUTPUT"
+
+      - name: Run tests in local image
+        run: |
+          PYTHON_VER="$(echo '${{ matrix.python-version }}' | sed 's|-dev$||')"
+          CTR_NAME="voiptests-${GITHUB_RUN_ID}-${GITHUB_RUN_ATTEMPT}-${{ strategy.job-index }}"
+          trap 'docker rm -f "${CTR_NAME}" >/dev/null 2>&1 || true' EXIT
+
+          docker create \
+            --name "${CTR_NAME}" \
+            --privileged \
+            --sysctl net.ipv6.conf.all.disable_ipv6=0 \
+            -e MM_TYPE='${{ inputs.mm-type }}' \
+            -e MM_BRANCH='${{ inputs.mm-branch }}' \
+            -e MM_AUTH='${{ matrix.mm-auth }}' \
+            -e RTPP_BRANCH='DOCKER' \
+            -e RTPPC_TYPE='${{ matrix.rtppc-type }}' \
+            -e ARTIFACT_FILES='${{ inputs.artifact-files }}' \
+            -e PYTHON_CMD="python${PYTHON_VER}" \
+            '${{ needs.build_ssut_image.outputs.image-ref }}' \
+            /bin/sh -lc '
+              set -e
+              cd /opt/voiptests
+              if ! command -v "${PYTHON_CMD}" >/dev/null 2>&1
+              then
+                PYTHON_CMD=python3
+              fi
+              export PYTHON_CMD
+              export PIP_BREAK_SYSTEM_PACKAGES=1
+
+              ${PYTHON_CMD} -m pip install --upgrade pip
+              ${PYTHON_CMD} -m pip install -r requirements.txt
+              if [ "${MM_TYPE}" = "b2bua" ]
+              then
+                ${PYTHON_CMD} -m pip install -U -r dist/b2bua/requirements.txt
+              fi
+
+              rm -rf test.logs
+              LOG_FILES="bob.log alice.log rtpproxy.log"
+              if [ -n "${ARTIFACT_FILES}" ]
+              then
+                LOG_FILES="${LOG_FILES} ${ARTIFACT_FILES}"
+              fi
+
+              RTPP_VERSION=debug sh -x ./test_run.sh
+              mkdir -p test.logs/debug
+              mv ${LOG_FILES} test.logs/debug
+
+              RTPP_VERSION=production sh -x ./test_run.sh
+              mkdir -p test.logs/production
+              mv ${LOG_FILES} test.logs/production
+            '
+
+          docker start -a "${CTR_NAME}"
+          rm -rf test.logs
+          docker cp "${CTR_NAME}:/opt/voiptests/test.logs" ./test.logs
 
-      - name: Test logs
+      - name: Upload test logs
         uses: actions/upload-artifact@v4
         with:
-          name: ${{ steps.transform_var.outputs.ARTNAME }}
+          name: ${{ steps.artifact_name.outputs.artname }}
           path: test.logs
         continue-on-error: true
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 58d33a1..9ceb513 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -1,118 +1,98 @@
-# This is a basic workflow to help you get started with Actions
-
 name: Alice->SSUT->Bob
 
-# Controls when the action will run. 
 on:
-  # Triggers the workflow on push or pull request events but only for the master branch
   push:
-#    branches: [ master ]
   pull_request:
-#    branches: [ master ]
-
   release:
     types: [created]
-
-  # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:
-
   schedule:
     - cron: "30 0 * * 0"
 
-# A workflow run is made up of one or more jobs that can run sequentially or in parallel
 jobs:
   # Alice->OpenSIPS->Bob
   opensips:
+    name: OpenSIPS (${{ matrix.mm-branch }})
     uses: ./.github/workflows/.main.yml
     with:
       mm-type: 'opensips'
       mm-branch: ${{ matrix.mm-branch }}
-      rtppc-type: ${{ matrix.rtppc-type }}
+      mm-auths: ${{ matrix.mm-auths }}
+      rtppc-types: ${{ matrix.rtppc-types }}
+      use-local-image: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.repo.fork }}
       artifact-files: 'opensips.cfg'
     strategy:
       fail-fast: false
       matrix:
-        mm-branch: ['master', '3.5', '3.4', '3.3', '3.2']
-        rtppc-type: ['unix', 'udp', 'udp6', 'tcp', 'tcp6']
         include:
-          - mm-branch: '2.4'
-            rtppc-type: 'unix'
-          - mm-branch: '2.4'
-            rtppc-type: 'udp'
-          - mm-branch: '2.4'
-            rtppc-type: 'udp6'
-          - mm-branch: '3.0'
-            rtppc-type: 'unix'
-          - mm-branch: '3.0'
-            rtppc-type: 'udp'
-          - mm-branch: '3.0'
-            rtppc-type: 'udp6'
+          - mm-branch: 'master'
+            mm-auths: '["", "passtr", "UAC", "UAS/auth", "UAS/auth_db/calculate_ha1", "UAS/auth_db/ha1"]'
+            rtppc-types: '["unix", "udp", "udp6", "tcp", "tcp6"]'
+          - mm-branch: '3.5'
+            mm-auths: '[""]'
+            rtppc-types: '["unix", "udp", "udp6", "tcp", "tcp6"]'
+          - mm-branch: '3.4'
+            mm-auths: '[""]'
+            rtppc-types: '["unix", "udp", "udp6", "tcp", "tcp6"]'
+          - mm-branch: '3.3'
+            mm-auths: '[""]'
+            rtppc-types: '["unix", "udp", "udp6", "tcp", "tcp6"]'
+          - mm-branch: '3.2'
+            mm-auths: '[""]'
+            rtppc-types: '["unix", "udp", "udp6", "tcp", "tcp6"]'
           - mm-branch: '3.1'
-            rtppc-type: 'unix'
-          - mm-branch: '3.1'
-            rtppc-type: 'udp'
-          - mm-branch: '3.1'
-            rtppc-type: 'udp6'
-
-  # Alice->OpenSIPS(RFC8760)->Bob
-  opensips_rfc8760:
-    uses: ./.github/workflows/.main.yml
-    with:
-      mm-type: 'opensips'
-      mm-auth: ${{ matrix.mm-auth }}
-      rtppc-type: ${{ matrix.rtppc-type }}
-      artifact-files: 'opensips.cfg'
-
-    strategy:
-      fail-fast: false
-      matrix:
-        rtppc-type: ['unix', 'udp', 'udp6', 'tcp', 'tcp6']
-        mm-auth: ['passtr', 'UAC', 'UAS/auth', 'UAS/auth_db/calculate_ha1', 'UAS/auth_db/ha1']
+            mm-auths: '[""]'
+            rtppc-types: '["unix", "udp", "udp6"]'
+          - mm-branch: '3.0'
+            mm-auths: '[""]'
+            rtppc-types: '["unix", "udp", "udp6"]'
+          - mm-branch: '2.4'
+            mm-auths: '[""]'
+            rtppc-types: '["unix", "udp", "udp6"]'
 
   # Alice->Sippy Python B2B->Bob
   sippy_py_b2bua:
+    name: Sippy Py-B2BUA (${{ matrix.mm-branch }})
     uses: ./.github/workflows/.main.yml
     with:
       mm-type: 'b2bua'
       mm-branch: ${{ matrix.mm-branch }}
-      rtppc-type: ${{ matrix.rtppc-type }}
-      python-version: ${{ matrix.python-version }}
+      python-versions: '["3.9", "3.10", "3.11", "3.12", "3.13-dev"]'
+      rtppc-types: '["unix", "cunix", "udp", "udp6", "tcp", "tcp6"]'
+      use-local-image: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.repo.fork }}
       artifact-files: 'b2bua.log'
     strategy:
       fail-fast: false
       matrix:
         mm-branch: ['master', 'PRACK']
-        rtppc-type: ['unix', 'cunix', 'udp', 'udp6', 'tcp', 'tcp6']
-        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13-dev']
 
   # Alice->Sippy GO B2B->Bob
   sippy_go_b2bua:
+    name: Sippy GO-B2BUA (${{ matrix.mm-branch }})
     uses: ./.github/workflows/.main.yml
     with:
       mm-type: 'go-b2bua'
-      rtppc-type: ${{ matrix.rtppc-type }}
+      rtppc-types: '["unix", "cunix", "udp", "udp6", "tcp", "tcp6"]'
+      use-local-image: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.repo.fork }}
       artifact-files: 'b2bua.log'
-    strategy:
-      fail-fast: false
-      matrix:
-        rtppc-type: ['unix', 'cunix', 'udp', 'udp6', 'tcp', 'tcp6']
 
   # Alice->Kamailio->Bob
   kamailio:
+    name: Kamailio (${{ matrix.mm-branch }})
     uses: ./.github/workflows/.main.yml
     with:
       mm-type: 'kamailio'
       mm-branch: ${{ matrix.mm-branch }}
-      rtppc-type: ${{ matrix.rtppc-type }}
+      rtppc-types: '["unix", "udp", "udp6"]'
+      use-local-image: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.repo.fork }}
       artifact-files: 'kamailio.cfg'
     strategy:
       fail-fast: false
       matrix:
         mm-branch: ['master', '6.0', '5.8', '5.7', '5.6', '5.5', '5.4', '5.3', '5.2', '5.1', '4.4']
-        rtppc-type: ['unix', 'udp', 'udp6']
 
   publish:
-    needs: [opensips, opensips_rfc8760, sippy_py_b2bua, sippy_go_b2bua, kamailio]
+    needs: [opensips, sippy_py_b2bua, sippy_go_b2bua, kamailio]
     if: github.event_name == 'release' && github.event.action == 'created'
     runs-on: ubuntu-latest
 
diff --git a/alice_main.py b/alice_main.py
index 3187e84..2d0a98c 100644
--- a/alice_main.py
+++ b/alice_main.py
@@ -26,6 +26,9 @@
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import sys, getopt
+import math
+
+from .contrib.objgraph import show_most_common_types
 
 from sippy.MsgBody import MsgBody
 from sippy.SipLogger import SipLogger
@@ -85,6 +88,14 @@ def main_func():
         if o == '-s':
             tcfg.signalling_only = True
             continue
+        if o == '-C':
+            if not a.startswith('='):
+                cpsval = float(a)
+                tcfg.cps = lambda now: cpsval
+            else:
+                cpsfunc = eval(F'lambda now: {a[1:]}')
+                tcfg.cps = cpsfunc
+            continue
     if len(ttype) > 0:
         tcfg.ttype = tuple(ttype)
 
@@ -101,4 +112,7 @@ def main_func():
     if not dry_run:
         ED2.loop()
 
+        print('\n-- Types Summary: --')
+        show_most_common_types(50)
+
         sys.exit(acore.rval)
diff --git a/bob_main.py b/bob_main.py
index be9f8bf..177586d 100644
--- a/bob_main.py
+++ b/bob_main.py
@@ -61,6 +61,9 @@
 
 BODIES_ALL = (body_audio, body_fax)
 
+def usage(args):
+    printf("bob.py -p xx -l yy -P zz -T tt -n aa -N bb -w cc -s")
+
 def main_func():
     global_config = {}
 
diff --git a/cibits/build_ssut_image.sh b/cibits/build_ssut_image.sh
new file mode 100755
index 0000000..f02c4d6
--- /dev/null
+++ b/cibits/build_ssut_image.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+set -eux
+
+apt-get update
+apt-get install -y --no-install-recommends \
+  python3 python3-pip \
+  gpp gdb tcpdump gcc libc6-dev git make ca-certificates \
+  libssl-dev flex bison
+
+if [ "${MM_TYPE}" = "go-b2bua" ]
+then
+  apt-get install -y --no-install-recommends golang-go
+fi
+
+if [ "${MM_TYPE}" = "kamailio" ]
+then
+  apt-get install -y --no-install-recommends libcurl4-gnutls-dev
+fi
+
+SKIP_PY_DEPS=1 /bin/sh -x ./install_depends/opensips.sh
+
+rm -rf /var/lib/apt/lists/*
diff --git a/functions b/functions
index 47e9f0d..f3c42bb 100755
--- a/functions
+++ b/functions
@@ -101,6 +101,7 @@ then
   BOB_TIMEOUT=90
   TEST_SET="${TEST_SET},11,12,13,14,reinv_brkn1,reinv_brkn2,reinv_bad_ack"
 fi
+TEST_SET="${TEST_SET},early_cancel_lost100"
 
 MM_ROOT="${MM_ROOT:-"${BUILDDIR}/dist/${MM_TYPE}"}"
 
@@ -109,10 +110,10 @@ then
   TEST_SET="${TEST_SET},inv_brkn1"
 fi
 
-#if [ "${MM_TYPE}" != "opensips" -o "${MM_BRANCH}" = "1.11" ]
-#then
-TEST_SET="${TEST_SET},early_cancel_lost100"
-#fi
+if [ "${MM_TYPE}" = "opensips" -a "${MM_BRANCH}" = "master" ]
+then
+  TEST_SET="${TEST_SET},nated_contact"
+fi
 
 #if [ "${MM_TYPE}" = "kamailio" ]
 #then
diff --git a/install_depends/opensips.sh b/install_depends/opensips.sh
index d44d645..897e720 100755
--- a/install_depends/opensips.sh
+++ b/install_depends/opensips.sh
@@ -72,7 +72,10 @@ fi
 
 if [ "${MM_TYPE}" = "b2bua" ]
 then
-  ${PYTHON_CMD} -m pip install -U -r b2bua/requirements.txt
+  if [ "${SKIP_PY_DEPS}" != "1" ]
+  then
+    ${PYTHON_CMD} -m pip install -U -r b2bua/requirements.txt
+  fi
 fi
 
 if [ "${MM_TYPE}" = "kamailio" ]
diff --git a/lib/alice_testcore.py b/lib/alice_testcore.py
index e9d5fd0..921be50 100644
--- a/lib/alice_testcore.py
+++ b/lib/alice_testcore.py
@@ -23,13 +23,15 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-##import sys
+import sys
+from signal import SIGINT
 ##sys.path.insert(0, 'dist/b2bua')
 
 from sippy.SipTransactionManager import SipTransactionManager
-from sippy.Time.Timeout import Timeout
+from sippy.Signal import Signal
+from sippy.Time.Timeout import Timeout, TimeoutAbsMono
 from sippy.Core.EventDispatcher import ED2
-from random import shuffle
+from random import shuffle, choice
 
 from .testcore_base import testcore_base
 
@@ -58,13 +60,14 @@
 from ..test_cases.reinv_frombob import a_test_reinv_frombob
 from ..test_cases.reinv_bad_ack import a_test_reinv_bad_ack
 from ..test_cases.inv_brkn1 import a_test_inv_brkn1
+from ..test_cases.nated_contact import a_test_nated_contact
 
 ALL_TESTS = (a_test1, a_test2, a_test3, a_test4, a_test5, a_test6, a_test7, \
   a_test8, a_test9, a_test10, a_test11, a_test12, a_test13, a_test14, \
   a_test_early_cancel, a_test_early_cancel_lost100, a_test_reinvite, \
   a_test_reinv_fail, a_test_reinv_brkn1, a_test_reinv_brkn2, \
   a_test_reinv_onhold, a_test_reinv_adelay, a_test_reinv_frombob, \
-  a_test_reinv_bad_ack, a_test_inv_brkn1)
+  a_test_reinv_bad_ack, a_test_inv_brkn1, a_test_nated_contact)
 
 class a_cfg(object):
     test_class = None
@@ -83,6 +86,9 @@ class a_test(testcore_base):
     stats_name = 'Alice'
     nsubtests_running = 0
     rval = 1
+    tcfg = None
+    last_ulen = 0
+    nextr = None
 
     def __init__(self, tcfg):
         self.setup_stm(tcfg)
@@ -103,10 +109,22 @@ def __init__(self, tcfg):
                     subtest_cfg.tcfg = tcfg.gen_tccfg(atype, signalling_only, \
                       self.subtest_done, cli)
                     atests.append(subtest_cfg)
-                    mode = 'signalling-only' if signalling_only else 'rtp-enabled'
-                    print(f'Scheduling test: {subtest_class.name} [{atype}, {mode}, {cli=}]')
+                    if tcfg.continuous:
+                        subtest_class.debug_lvl = -1
+                        subtest_class.godead_timeout = 1.0
+                    else:
+                        mode = 'signalling-only' if signalling_only else 'rtp-enabled'
+                        print(f'Scheduling test: {subtest_class.name} [{atype}, {mode}, {cli=}]')
         atests = [x for x in atests if not x.disabled]
         super().__init__(tcfg)
+        if tcfg.continuous:
+            self.atests = atests
+            self.ntime = tcfg.ntime.getCopy()
+            #Timeout(self.runnext, 0.1, -1)
+            self.setup_continuous_stats()
+            self.runnext()
+            Signal(SIGINT, self.deorbit)
+            return
         shuffle(atests)
         for subtest_cfg in atests:
             subtest = subtest_cfg.init_test()
@@ -118,3 +136,27 @@ def __init__(self, tcfg):
     def _on_no_subtests_left(self):
         super()._on_no_subtests_left()
         ED2.breakLoop()
+
+    def deorbit(self, signum = None):
+        self.nextr.cancel()
+        Timeout(self.slowexit, 0.1, -1)
+        Timeout(self.timeout, 140.0)
+
+    def slowexit(self):
+        self.update_stats()
+        if self.nsubtests_running > 0:
+            return
+        sys.stdout.write('\n')
+        sys.stdout.flush()
+        ED2.breakLoop()
+
+    def runnext(self):
+        subtest_cfg = choice(self.atests)
+        subtest = subtest_cfg.init_test()
+        self.nsubtests_running += 1
+        if self.tcfg.cps != None:
+            self.ntime.offset(1.0 / self.tcfg.cps(self.ntime - self.tcfg.ntime))
+            self.nextr = TimeoutAbsMono(self.runnext, self.ntime)
+        else:
+            self.runnext()
+        self.update_stats()
diff --git a/lib/bob_testcore.py b/lib/bob_testcore.py
index 0ed00ee..5e6bc16 100644
--- a/lib/bob_testcore.py
+++ b/lib/bob_testcore.py
@@ -23,11 +23,14 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-##import sys
+import sys
+from signal import SIGUSR1
 ##sys.path.insert(0, 'dist/b2bua')
 
 from sippy.Time.Timeout import Timeout
 from sippy.SipTransactionManager import SipTransactionManager
+from sippy.Signal import Signal
+
 from random import random
 
 from .test_config import fillhostport, SIPPY_RTP_OUSER
@@ -58,13 +61,14 @@
 from ..test_cases.reinv_frombob import b_test_reinv_frombob
 from ..test_cases.reinv_bad_ack import b_test_reinv_bad_ack
 from ..test_cases.inv_brkn1 import b_test_inv_brkn1
+from ..test_cases.nated_contact import b_test_nated_contact
 
 ALL_TESTS = (b_test1, b_test2, b_test3, b_test4, b_test5, b_test6, b_test7, \
   b_test8, b_test9, b_test10, b_test11, b_test12, b_test13, b_test14, \
   b_test_early_cancel, b_test_early_cancel_lost100, b_test_reinvite, \
   b_test_reinv_fail, b_test_reinv_brkn1, b_test_reinv_brkn2, \
   b_test_reinv_onhold, b_test_reinv_adelay, b_test_reinv_frombob, \
-  b_test_reinv_bad_ack, b_test_inv_brkn1)
+  b_test_reinv_bad_ack, b_test_inv_brkn1, b_test_nated_contact)
 
 class STMHooks(object):
     lossemul = 0
@@ -97,13 +101,30 @@ class b_test(testcore_base):
     rval = 1
     nsubtests_running = 0
     tcfg: 'test_config' = None
+    debug = False
+    spinor = None
+    last_ulen = 0
+    active_subtests = None
 
     def __init__(self, tcfg:'test_config'):
         self.setup_stm(tcfg)
         super().__init__(tcfg)
-        Timeout(self.timeout, tcfg.test_timeout, 1)
+        if not tcfg.continuous:
+            Timeout(self.timeout, tcfg.test_timeout, 1)
+        else:
+            self.active_subtests = []
+            self.setup_continuous_stats()
+            Signal(SIGUSR1, self.dumpcalls)
+
+    def dumpcalls(self):
+        sys.stderr.write('BOB: Active tests:\n')
+        for c in self.active_subtests:
+            sys.stderr.write('\t%d %s\n' % (id(c), str(c)))
+        sys.stderr.flush()
 
     def recvRequest(self, req, sip_t):
+        if self.debug:
+            print('recvRequest')
         if req.getHFBody('to').getTag() is not None:
             # Request within dialog, but no such dialog
             return (req.genResponse(481, 'Call Leg/Transaction Does Not Exist'), None, None)
@@ -131,11 +152,17 @@ def recvRequest(self, req, sip_t):
 
             tccfg = self.tcfg.gen_tccfg(atype, signalling_only, self.subtest_done)
 
+            if self.tcfg.continuous:
+                tclass.debug_lvl = -1
+                tclass.godead_timeout = 1.0
             subtest = tclass(tccfg)
             test_id = req.getHFBody('to').getUrl().username
             subtest.mightfail = test_id in self.tcfg.tests_mightfail
 
             self.nsubtests_running += 1
+            if self.tcfg.continuous:
+                self.active_subtests.append(subtest)
+                self.update_stats()
             self.rval += 1
 
             bidx = 0 if not tccfg.signalling_only or random() < 0.5 else 1
@@ -149,6 +176,9 @@ def recvRequest(self, req, sip_t):
                 resp.appendHeaders(ce.challenges)
                 self.nsubtests_running -= 1
                 self.rval -= 1
+                if self.tcfg.continuous:
+                    self.active_subtests.remove(subtest)
+                    self.update_stats()
                 resp.lossemul = STMHooks()
                 resp.lossemul.dupemul = 0.001
                 return (resp, None, None)
@@ -161,3 +191,6 @@ def timeout(self):
         if self.nsubtests_running == 0 and self.rval == 1:
             self.rval = 0
         super().timeout()
+
+    def _subtest_done_continuous(self, subtest):
+        self.active_subtests.remove(subtest)
diff --git a/lib/spinor.py b/lib/spinor.py
new file mode 100644
index 0000000..206e627
--- /dev/null
+++ b/lib/spinor.py
@@ -0,0 +1,15 @@
+class spinor(object):
+    i = 0
+    busy_states = '-\\|/'
+    idle_states = '.oOo'
+    idle = False
+
+    def tick(self):
+        if self.idle:
+            st = self.idle_states
+        else:
+            st = self.busy_states
+        ri = self.i % len(st)
+        rv = st[ri]
+        self.i += 1
+        return rv
diff --git a/lib/test_config.py b/lib/test_config.py
index 2b2fedb..6faf60b 100644
--- a/lib/test_config.py
+++ b/lib/test_config.py
@@ -65,6 +65,7 @@ class test_case_config(object):
     check_media_ips = None
     cli = None
     signalling_only = False
+    continuous = False
 
     def __init__(self, nh_address):
         self.nh_address = nh_address
@@ -93,7 +94,7 @@ def checkhostport(self, sdp_body):
         return (True, 'all good')
 
 class test_config(object):
-    getopts = 'p:l:P:T:n:N:w:m:'
+    getopts = 'p:l:P:T:n:N:w:m:c:'
     global_config = None
     ttype = ('IP4', 'IP6')
     body = None
@@ -107,8 +108,12 @@ class test_config(object):
     tests_mightfail = tuple()
     signalling_only = False
     pre_wait = None
+    continuous = False
+    cps = None
+    ntime = None
 
     def gen_tccfg(self, atype, signalling_only, done_cb, cli=None):
+        self.ntime = MonoTime()
         if atype == 'IP4':
             nh_address = self.nh_address4
         else:
@@ -127,6 +132,7 @@ def gen_tccfg(self, atype, signalling_only, done_cb, cli=None):
         tccfg.atype = atype
         tccfg.portrange = self.portrange
         tccfg.signalling_only = signalling_only
+        tccfg.continuous = self.continuous
         return tccfg
 
     def _parse_common_opt(self, o, a):
@@ -161,6 +167,9 @@ def _parse_common_opt(self, o, a):
         if o == '-m':
             self.tests_mightfail = tuple(a.split(','))
             return True
+        if o == '-c':
+            self.continuous = True
+            return True
         return False
 
     def __init__(self, global_config, opts = None):
diff --git a/lib/testcore_base.py b/lib/testcore_base.py
index 2662f67..84e9517 100644
--- a/lib/testcore_base.py
+++ b/lib/testcore_base.py
@@ -26,8 +26,11 @@
 import sys
 
 from sippy.Core.EventDispatcher import ED2
+from sippy.Math.recfilter import recfilter
+from sippy.Time.Timeout import Timeout
 
 from .sleep_abs_mono import sleep_abs_mono
+from .spinor import spinor
 
 class testcore_base(object):
     stm_class = None
@@ -44,15 +47,42 @@ def setup_stm(self, tcfg):
         self.stm_class.model_udp_server[1].nworkers = 1
         tcfg.global_config['_sip_tm'] = self.stm_class(tcfg.global_config, self.recvRequest)
 
+    def setup_continuous_stats(self):
+        self.spinor = spinor()
+        self.rcf = recfilter(0.999, 1.0)
+        self.update_stats()
+        Timeout(self.idle_update, 1.0, -1)
+
     def recvRequest(self, req, sip_t):
         return (req.genResponse(501, 'Not Implemented'), None, None)
 
     def timeout(self):
         ED2.breakLoop()
 
+    def update_stats(self):
+        if self.nsubtests_running == 0:
+            self.spinor.idle = True
+        else:
+            self.spinor.idle = False
+        omsg = '\r%s: %d tests running %s, %f' % (self.stats_name, \
+          self.nsubtests_running, self.spinor.tick(), self.rcf.lastval)
+        sys.stdout.write(omsg)
+        if len(omsg) < self.last_ulen:
+            pad = ' ' * (self.last_ulen - len(omsg))
+            sys.stdout.write(pad)
+        sys.stdout.flush()
+        self.last_ulen = len(omsg)
+
+    def idle_update(self):
+        if self.spinor.idle:
+            self.update_stats()
+
     def _subtest_done_common(self, subtest):
         pass
 
+    def _subtest_done_continuous(self, subtest):
+        pass
+
     def _on_no_subtests_left(self):
         pass
 
@@ -61,5 +91,12 @@ def subtest_done(self, subtest):
         self._subtest_done_common(subtest)
         if subtest.rval == 0:
             self.rval -= 1
-        if self.nsubtests_running == 0:
+        if self.tcfg.continuous:
+            self._subtest_done_continuous(subtest)
+            if subtest.rval == 0:
+                self.rcf.apply(1.0)
+            else:
+                self.rcf.apply(0.0)
+            self.update_stats()
+        elif self.nsubtests_running == 0:
             self._on_no_subtests_left()
diff --git a/requirements.txt b/requirements.txt
index 7619d8f..60ddd59 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1 @@
-sippy
+git+https://github.com/sippy/b2bua.git@master
diff --git a/scenarios/simple/opensips.cfg.in b/scenarios/simple/opensips.cfg.in
index 39552b3..c604cd5 100644
--- a/scenarios/simple/opensips.cfg.in
+++ b/scenarios/simple/opensips.cfg.in
@@ -15,6 +15,7 @@ loadmodule "sipmsgops/sipmsgops.so"
 loadmodule "sl/sl.so"
 loadmodule "tm/tm.so"
 loadmodule "rr/rr.so"
+loadmodule "nathelper/nathelper.so"
 loadmodule "maxfwd/maxfwd.so"
 #if RTPPC_TYPE == rtp.io
 loadmodule "rtp.io/rtp.io.so"
@@ -38,6 +39,12 @@ modparam("rtp.io", "rtpproxy_args", $$"-m 12000 -M 15000 RTPP_LISTEN"$$)
 modparam("rtpproxy", "rtpproxy_sock", RTPP_SOCK_TEST)
 #endif
 
+#if OPENSIPS_VER_FULL == master || OPENSIPS_VER > 33
+#define NAT_PCONTACT "private-contact"
+#else
+#define NAT_PCONTACT INT(1)
+#endif
+
 #if OPENSIPS_VER != 24 && OPENSIPS_VER != 30
 socket=udp:127.0.0.1:5060
 socket=udp:[::1]:5060
@@ -88,13 +95,27 @@ route {
     };
 
     if (is_method("BYE")) {
-        xlog("    calling rtpproxy_unforce()\n");
+        xlog("  calling rtpproxy_unforce()\n");
         rtpproxy_unforce();
     };
 
     record_route();
 
+    if (is_method("INVITE") && !has_totag() && nat_uac_test(NAT_PCONTACT)) {
+        xlog("  NAT contact detected\n");
+#if OPENSIPS_VER_FULL == master
+        if (add_contact_alias()) {
+            xlog("    adding alias\n");
+        };
+#endif
+    };
+
     if (loose_route()) {
+#if OPENSIPS_VER_FULL == master
+        if (handle_ruri_alias()) {
+            xlog("  alias removed from the R-URI\n");
+        };
+#endif
         t_relay();
         exit;
     };
@@ -114,6 +135,14 @@ onreply_route[1]
 {
     xlog("OpenSIPS received a reply $rs/$rm from $si\n");
     if (STATUS =~ "(183)|2[0-9][0-9]") {
+        if (nat_uac_test(NAT_PCONTACT)) {
+            xlog("  NAT contact detected\n");
+#if OPENSIPS_VER_FULL == master
+            if (add_contact_alias()) {
+                xlog("    adding alias\n");
+            };
+#endif
+        };
         xlog("  calling search()\n");
         if(!search("^Content-Length:[ ]*0")) {
             xlog("    calling rtpproxy_answer()\n");
@@ -126,6 +155,6 @@ onreply_route[1]
 failure_route[1]
 {
     xlog("OpenSIPS handling $rm failure in from $si in failure_route[1]\n");
-    xlog("    calling rtpproxy_unforce()\n");
+    xlog("  calling rtpproxy_unforce()\n");
     rtpproxy_unforce();
 }
diff --git a/test_cases/nated_contact.py b/test_cases/nated_contact.py
new file mode 100644
index 0000000..bf1a1f2
--- /dev/null
+++ b/test_cases/nated_contact.py
@@ -0,0 +1,74 @@
+# Copyright (c) 2025 Sippy Software, Inc. All rights reserved.
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification,
+# are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this
+# list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation and/or
+# other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from .reinv_frombob import a_test_reinv_frombob, b_test_reinv_frombob
+from .TExceptions import ScenarioFailure
+
+from sippy.SipAddress import SipAddress
+from sippy.SipContact import SipContact
+from sippy.SipURL import SipURL
+from sippy.UA import UA
+
+
+class _ReinviteTrackingUA(UA):
+    """UA variant that keeps the R-URI of inbound in-dialog INVITEs."""
+
+    def recvRequest(self, req, *args, **kwargs):
+        if req.getMethod() == 'INVITE':
+            self.last_in_dialog_invite_ruri = str(req.getRURI())
+        return super(_ReinviteTrackingUA, self).recvRequest(req, *args, **kwargs)
+
+class a_test_nated_contact(a_test_reinv_frombob):
+    cld = 'bob_nated_contact'
+    cli = 'alice_nated_contact'
+    name = f'{a_test_reinv_frombob.name}: NATed Contact preserved on re-INVITE'
+    compact_sip = False
+    nat_contact_ip = '192.168.255.10'
+    nat_contact_port = 5090
+
+    def build_ua(self, tccfg):
+        uaO = super(a_test_nated_contact, self).build_ua(tccfg, UA_class=_ReinviteTrackingUA)
+        nat_contact = self._build_nat_contact()
+        uaO.lContact = nat_contact
+        self.expected_contact_uri = str(nat_contact.getUrl())
+        return uaO
+
+    def _build_nat_contact(self):
+        nat_url = SipURL(username = self.cli, host = self.nat_contact_ip,
+          port = self.nat_contact_port)
+        nat_address = SipAddress(url = nat_url)
+        return SipContact(address = nat_address)
+
+    def on_reinvite_connected(self, ua):
+        super(a_test_nated_contact, self).on_reinvite_connected(ua)
+        ruri = getattr(ua, 'last_in_dialog_invite_ruri', None)
+        if ruri != self.expected_contact_uri:
+            self.nerrs += 1
+            print(ScenarioFailure('%s: expected re-INVITE R-URI %s, got %s' %
+              (self.failed_msg(), self.expected_contact_uri, ruri)))
+
+class b_test_nated_contact(b_test_reinv_frombob):
+    cli = a_test_nated_contact.cld
+    name = a_test_nated_contact.name
diff --git a/test_cases/t1.py b/test_cases/t1.py
index 4bb0bf9..c740af2 100644
--- a/test_cases/t1.py
+++ b/test_cases/t1.py
@@ -256,6 +256,8 @@ def report_rtp(self):
         stats = self._rtp_shutdown_stats()
         if self._rtp_error is not None and self.debug_lvl > -1:
             print('%s: RTP error: %s' % (self.my_name(), self._rtp_error))
+        if self.tccfg.continuous:
+            return
         if self._rtp_target is None:
             print('%s: RTP stats: no session' % self.my_name())
             return
diff --git a/test_run.sh b/test_run.sh
index 2d5cf14..92945b2 100755
--- a/test_run.sh
+++ b/test_run.sh
@@ -332,6 +332,8 @@ then
   fi
 fi
 
+${SUDO} find /tmp/ -type f -name core\*
+
 report_rc_log "${ALICE_RC}" "${MM_CFG} alice.log bob.log rtpproxy.log ${MM_LOG}" "Checking if Alice is happy"
 report_rc_log "${BOB_RC}" "${MM_CFG} bob.log alice.log rtpproxy.log ${MM_LOG}" "Checking if Bob is happy"