diff --git a/src/sip/IMHandler.cpp b/src/sip/IMHandler.cpp
index 703eba2a..9190d99c 100644
--- a/src/sip/IMHandler.cpp
+++ b/src/sip/IMHandler.cpp
@@ -8,7 +8,6 @@
 
 #include "SIPCall.h"
 #include "SIPAccount.h"
-#include "UserInfo.h"
 #include "IMHandler.h"
 #include "ViewHelper.h"
 
@@ -19,13 +18,14 @@ IMHandler::IMHandler(SIPCall *parent) : QObject(parent), m_call(parent)
     ReadOnlyConfdSettings settings;
 
     if (settings.contains("jitsi/url")) {
-
         settings.beginGroup("jitsi");
         m_jitsiBaseURL = settings.value("url", "").toString();
         m_jitsiPreconfig = settings.value("preconfig", false).toBool();
 
         settings.endGroup();
     }
+
+    m_dtmfDebugConfigured = settings.value("generic/dtmfDebug", false).toBool();
 }
 
 bool IMHandler::process(const QString &contentType, const QString &message)
@@ -88,6 +88,33 @@ bool IMHandler::process(const QString &contentType, const QString &message)
         return true;
     }
 
+    // Call delays
+    else if (path == "callDelay" && dtmfDebugEnabled()) {
+        bool validTimestamp = false;
+        qint64 timestamp = 0;
+        QString digit;
+        QUrlQuery q(callUrl);
+        auto qitems = q.queryItems();
+
+        for (auto &qi : std::as_const(qitems)) {
+            if (qi.first == "timestamp") {
+                timestamp = qi.second.toLongLong(&validTimestamp);
+            }
+            if (qi.first == "digit") {
+                digit = qi.second;
+            }
+        }
+
+        if (!validTimestamp) {
+            qCWarning(lcIMHandler) << "invalid call delay timestamp received";
+            return false;
+        }
+
+        m_call->setCallDelayTx(timestamp, digit);
+
+        return true;
+    }
+
     return false;
 }
 
@@ -153,6 +180,9 @@ bool IMHandler::sendCapabilities()
         m_ownCapabilities.push_back("jitsi");
     }
 
+    q.addQueryItem("callDelay", "1");
+    m_ownCapabilities.push_back("callDelay");
+
     QUrl jitsiUrl("gonnect:");
     jitsiUrl.setPath("capabilities");
     jitsiUrl.setQuery(q);
diff --git a/src/sip/IMHandler.h b/src/sip/IMHandler.h
index 5d3799e3..3048428d 100644
--- a/src/sip/IMHandler.h
+++ b/src/sip/IMHandler.h
@@ -18,6 +18,11 @@ class IMHandler : public QObject
     {
         return !m_jitsiBaseURL.isEmpty() && m_capabilities.contains("jitsi");
     }
+    bool dtmfDebugEnabled() const
+    {
+        return m_dtmfDebugConfigured && m_capabilities.contains("callDelay");
+    }
+
     bool process(const QString &contentType, const QString &message);
 
     bool capabilitiesSent() const { return m_capabilitiesSent; }
@@ -53,4 +58,5 @@ class IMHandler : public QObject
 
     bool m_capabilitiesSent = false;
     bool m_jitsiPreconfig = false;
+    bool m_dtmfDebugConfigured = false;
 };
diff --git a/src/sip/SIPCall.cpp b/src/sip/SIPCall.cpp
index a9f662ac..80b6ca66 100644
--- a/src/sip/SIPCall.cpp
+++ b/src/sip/SIPCall.cpp
@@ -1,5 +1,7 @@
 #include <QLoggingCategory>
 #include <QRegularExpression>
+#include <QUrl>
+#include <qurlquery.h>
 
 #include "SIPCall.h"
 #include "SIPCallManager.h"
@@ -72,6 +74,21 @@ SIPCall::SIPCall(SIPAccount *account, int callId, const QString &contactId, bool
             globalCallState.holdAllCalls(this);
         }
     }
+
+    m_callDelayCycleTimer.setInterval(10s);
+    connect(&m_callDelayCycleTimer, &QTimer::timeout, this, [this]() {
+        QString digit = QString("%1").arg((m_callDelayCounter % 9) + 1);
+        m_callDelayCounter++;
+
+        requestCallDelay(digit);
+    });
+
+    connect(this, &SIPCall::capabilitiesChanged, [this]() {
+        if (m_imHandler->dtmfDebugEnabled() && isEstablished()
+            && !m_callDelayCycleTimer.isActive()) {
+            m_callDelayCycleTimer.start();
+        }
+    });
 }
 
 SIPCall::~SIPCall()
@@ -265,6 +282,10 @@ void SIPCall::onCallState(pj::OnCallStateParam &prm)
         m_isEstablished = false;
         m_earlyCallState = false;
 
+        if (m_imHandler->dtmfDebugEnabled() && m_callDelayCycleTimer.isActive()) {
+            m_callDelayCycleTimer.stop();
+        }
+
         break;
 
     default:
@@ -348,16 +369,10 @@ void SIPCall::onInstantMessageStatus(pj::OnInstantMessageStatusParam &prm)
     qCWarning(lcSIPCall) << "failed to send message:" << prm.code << prm.reason;
 }
 
-pj::AudioMedia *SIPCall::audioMedia() const
+void SIPCall::onDtmfDigit(pj::OnDtmfDigitParam &prm)
 {
-    const auto callInfo = getInfo();
-
-    for (unsigned i = 0; i < callInfo.media.size(); ++i) {
-        if (callInfo.media[i].type == PJMEDIA_TYPE_AUDIO) {
-            return static_cast<pj::AudioMedia *>(getMedia(i));
-        }
-    }
-    return nullptr;
+    // INFO: Currently only used for DTMF call latency debugging
+    setCallDelayRx(QDateTime::currentMSecsSinceEpoch(), QString::fromStdString(prm.digit));
 }
 
 void SIPCall::onCallTsxState(pj::OnCallTsxStateParam &prm)
@@ -377,6 +392,18 @@ void SIPCall::onCallTsxState(pj::OnCallTsxStateParam &prm)
     }
 }
 
+pj::AudioMedia *SIPCall::audioMedia() const
+{
+    const auto callInfo = getInfo();
+
+    for (unsigned i = 0; i < callInfo.media.size(); ++i) {
+        if (callInfo.media[i].type == PJMEDIA_TYPE_AUDIO) {
+            return static_cast<pj::AudioMedia *>(getMedia(i));
+        }
+    }
+    return nullptr;
+}
+
 bool SIPCall::hold()
 {
     pj::CallOpParam op(true);
@@ -646,3 +673,50 @@ void SIPCall::addMetadata(const QString &data)
 
     Q_EMIT metadataChanged();
 }
+
+void SIPCall::requestCallDelay(QString digit)
+{
+    // DMTF
+    QString timestamp = QString("%1").arg(QDateTime::currentMSecsSinceEpoch());
+    auto &cm = SIPCallManager::instance();
+    cm.sendDtmf(m_account->id(), getId(), digit);
+
+    // IM
+    pj::SendInstantMessageParam prm;
+    prm.contentType = "application/x-www-form-urlencoded";
+
+    QUrlQuery q;
+    q.addQueryItem("timestamp", timestamp);
+    q.addQueryItem("digit", digit);
+
+    QUrl delayUrl("gonnect:");
+    delayUrl.setPath("callDelay");
+    delayUrl.setQuery(q);
+    prm.content = delayUrl.toString().toStdString();
+
+    try {
+        sendInstantMessage(prm);
+    } catch (pj::Error &err) {
+        qCWarning(lcSIPCall) << "failed to send call delay data:" << err.info();
+    }
+}
+
+void SIPCall::setCallDelayTx(qint64 timestamp, QString digit)
+{
+    m_callDelayTx.first = timestamp;
+    m_callDelayTx.second = digit;
+}
+
+void SIPCall::setCallDelayRx(qint64 timestamp, QString digit)
+{
+    m_callDelayRx.first = timestamp;
+    m_callDelayRx.second = digit;
+
+    if (m_callDelayRx.second != m_callDelayTx.second) {
+        m_callDelay = -1;
+    } else {
+        m_callDelay = m_callDelayRx.first - m_callDelayTx.first;
+    }
+
+    Q_EMIT callDelayChanged();
+}
diff --git a/src/sip/SIPCall.h b/src/sip/SIPCall.h
index 88c0b187..29592517 100644
--- a/src/sip/SIPCall.h
+++ b/src/sip/SIPCall.h
@@ -1,6 +1,7 @@
 #pragma once
 #include <QObject>
 #include <QPointer>
+#include <QTimer>
 #include <QDateTime>
 #include <pjsua2.hpp>
 
@@ -28,6 +29,7 @@ class SIPCall : public ICallState, public pj::Call
     virtual void onCallMediaState(pj::OnCallMediaStateParam &prm) override;
     virtual void onInstantMessage(pj::OnInstantMessageParam &prm) override;
     virtual void onInstantMessageStatus(pj::OnInstantMessageStatusParam &prm) override;
+    virtual void onDtmfDigit(pj::OnDtmfDigitParam &prm) override;
     virtual void onCallTsxState(pj::OnCallTsxStateParam &prm) override;
 
     SIPAccount *account() const { return m_account; };
@@ -50,6 +52,11 @@ class SIPCall : public ICallState, public pj::Call
     bool hasMetadata() const { return m_hasMetadata; }
     QList<ResponseItem *> metadata() { return m_metadata; };
 
+    void requestCallDelay(QString digit);
+
+    void setCallDelayTx(qint64 timestamp, QString digit);
+    void setCallDelayRx(qint64 timestamp, QString digit);
+
     bool hold();
     bool unhold();
     bool isHolding() const { return m_isHolding; }
@@ -64,6 +71,8 @@ class SIPCall : public ICallState, public pj::Call
     /// The time when the call was established (i.e. answered); invalid QDateTime if not established
     QDateTime establishedTime() const { return m_establishedTime; }
 
+    int callDelay() const { return m_callDelay; }
+
     bool earlyCallState() const { return m_earlyCallState; }
 
     virtual ContactInfo remoteContactInfo() const override { return m_contactInfo; }
@@ -81,6 +90,7 @@ class SIPCall : public ICallState, public pj::Call
     void capabilitiesChanged();
     void contactChanged();
     void metadataChanged();
+    void callDelayChanged();
 
 private Q_SLOTS:
     void updateIsBlocked();
@@ -99,6 +109,12 @@ private Q_SLOTS:
 
     QList<ResponseItem *> m_metadata;
 
+    QTimer m_callDelayCycleTimer;
+    QPair<qint64, QString> m_callDelayTx;
+    QPair<qint64, QString> m_callDelayRx;
+    int m_callDelayCounter = 0;
+    int m_callDelay = -1;
+
     pj::AudioMedia *m_aud_med = NULL;
     IMHandler *m_imHandler = nullptr;
 
diff --git a/src/sip/SIPCallManager.cpp b/src/sip/SIPCallManager.cpp
index afd64550..33cd10a4 100644
--- a/src/sip/SIPCallManager.cpp
+++ b/src/sip/SIPCallManager.cpp
@@ -687,6 +687,8 @@ void SIPCallManager::addCall(SIPCall *call)
             [call, this]() { Q_EMIT callContactChanged(call); });
     connect(call, &SIPCall::metadataChanged, this,
             [call, this]() { Q_EMIT metadataChanged(call); });
+    connect(call, &SIPCall::callDelayChanged, this,
+            [call, this]() { Q_EMIT callDelayChanged(call); });
 
     connect(call, &SIPCall::missed, this, [this, call]() {
         if (call->isBlocked()) {
diff --git a/src/sip/SIPCallManager.h b/src/sip/SIPCallManager.h
index cd96106e..f333cbf7 100644
--- a/src/sip/SIPCallManager.h
+++ b/src/sip/SIPCallManager.h
@@ -116,6 +116,7 @@ class SIPCallManager : public QObject
     void isConferenceModeChanged();
     void callContactChanged(SIPCall *call);
     void metadataChanged(SIPCall *call);
+    void callDelayChanged(SIPCall *call);
     void capabilitiesChanged(SIPCall *call);
     void audioLevelChanged(SIPCall *call, qreal level);
     void showCallWindow();
diff --git a/src/ui/CallsModel.cpp b/src/ui/CallsModel.cpp
index ca39556c..a0d9febe 100644
--- a/src/ui/CallsModel.cpp
+++ b/src/ui/CallsModel.cpp
@@ -23,6 +23,7 @@ CallsModel::CallsModel(QObject *parent) : QAbstractListModel{ parent }
         if (index >= 0) {
             callInfo->isEstablished = call->isEstablished();
             callInfo->established = call->establishedTime();
+            callInfo->callDelay = call->callDelay();
             callInfo->hasCapabilityJitsi = call->hasCapability("jitsi") && callInfo->isEstablished;
 
             auto idx = createIndex(index, 0);
@@ -30,11 +31,23 @@ CallsModel::CallsModel(QObject *parent) : QAbstractListModel{ parent }
                                {
                                        static_cast<int>(Roles::IsEstablished),
                                        static_cast<int>(Roles::EstablishedTime),
+                                       static_cast<int>(Roles::CallDelay),
                                        static_cast<int>(Roles::HasCapabilityJitsi),
                                });
         }
     });
 
+    connect(&callManager, &SIPCallManager::callDelayChanged, this, [this](SIPCall *call) {
+        auto callInfo = m_callsHash.value(call->getId());
+        const auto index = m_calls.indexOf(callInfo);
+        if (index >= 0) {
+            callInfo->callDelay = call->callDelay();
+
+            auto idx = createIndex(index, 0);
+            Q_EMIT dataChanged(idx, idx, { static_cast<int>(Roles::CallDelay) });
+        }
+    });
+
     connect(&callManager, &SIPCallManager::metadataChanged, this, [this](SIPCall *call) {
         auto callInfo = m_callsHash.value(call->getId());
         const auto index = m_calls.indexOf(callInfo);
@@ -136,6 +149,7 @@ QHash<int, QByteArray> CallsModel::roleNames() const
         { static_cast<int>(Roles::Company), "company" },
         { static_cast<int>(Roles::IsEstablished), "isEstablished" },
         { static_cast<int>(Roles::EstablishedTime), "establishedTime" },
+        { static_cast<int>(Roles::CallDelay), "callDelay" },
         { static_cast<int>(Roles::IsHolding), "isHolding" },
         { static_cast<int>(Roles::IsBlocked), "isBlocked" },
         { static_cast<int>(Roles::StatusCode), "statusCode" },
@@ -179,6 +193,7 @@ void CallsModel::updateCalls()
         callInfo->accountId = qobject_cast<SIPAccount *>(call->parent())->id();
         callInfo->remoteUri = call->sipUrl();
         callInfo->established = call->establishedTime();
+        callInfo->callDelay = call->callDelay();
         callInfo->isEstablished = call->isEstablished();
         callInfo->isIncoming = call->isIncoming();
         callInfo->isBlocked = call->isBlocked();
@@ -255,6 +270,9 @@ QVariant CallsModel::data(const QModelIndex &index, int role) const
     case static_cast<int>(Roles::EstablishedTime):
         return callInfo->established;
 
+    case static_cast<int>(Roles::CallDelay):
+        return callInfo->callDelay;
+
     case static_cast<int>(Roles::IsIncoming):
         return callInfo->isIncoming;
 
diff --git a/src/ui/CallsModel.h b/src/ui/CallsModel.h
index d7f07942..1d73bcc6 100644
--- a/src/ui/CallsModel.h
+++ b/src/ui/CallsModel.h
@@ -30,6 +30,7 @@ class CallsModel : public QAbstractListModel
         qreal incomingAudioLevel = 0.0;
         bool hasMetadata = false;
         QDateTime established;
+        int callDelay = -1;
         ContactInfo contactInfo;
         pjsip_status_code statusCode = PJSIP_SC_NULL;
     };
@@ -46,6 +47,7 @@ class CallsModel : public QAbstractListModel
         Company,
         IsEstablished,
         EstablishedTime,
+        CallDelay,
         IsHolding,
         IsBlocked,
         StatusCode,
diff --git a/src/ui/components/CallButtonBar.qml b/src/ui/components/CallButtonBar.qml
index 6672c897..8cd81e43 100644
--- a/src/ui/components/CallButtonBar.qml
+++ b/src/ui/components/CallButtonBar.qml
@@ -1,5 +1,6 @@
 pragma ComponentBehavior: Bound
 
+import QtCore
 import QtQuick
 import QtQuick.Controls.Material
 import base
@@ -22,6 +23,7 @@ Item {
     readonly property bool isFinished: control.callItem?.isFinished ?? false
     readonly property bool isIncoming: control.callItem?.isIncoming ?? false
     readonly property bool hasCapabilityJitsi: control.callItem?.hasCapabilityJitsi ?? false
+    readonly property int callDelay: control.callItem?.callDelay ?? -1
 
     readonly property bool areInCallButtonsEnabled: control.isEstablished && !control.isFinished
 
@@ -60,14 +62,32 @@ Item {
         }
     }
 
-    Label {
-        id: elapsedTimeLabel
-        color: Theme.secondaryTextColor
-        text: "🕓  " + ViewHelper.secondsToNiceText(internal.elapsedSeconds)
+    Row {
+        spacing: 20
+        leftPadding: 20
         anchors {
-            verticalCenter: parent.verticalCenter
+            top: parent.top
+            bottom: parent.bottom
             left: parent.left
-            leftMargin: 20
+        }
+
+        Label {
+            id: elapsedTimeLabel
+            color: Theme.secondaryTextColor
+            text: "🕓  " + ViewHelper.secondsToNiceText(internal.elapsedSeconds)
+            anchors {
+                verticalCenter: parent.verticalCenter
+            }
+        }
+
+        Label {
+            id: dtmfDebugLabel
+            visible: control.callDelay > 0
+            color: Theme.secondaryTextColor
+            text: "⚠  " + control.callDelay + " ms"
+            anchors {
+                verticalCenter: parent.verticalCenter
+            }
         }
     }
 
diff --git a/src/ui/components/CallItem.qml b/src/ui/components/CallItem.qml
index 9bba24e2..dd41009e 100644
--- a/src/ui/components/CallItem.qml
+++ b/src/ui/components/CallItem.qml
@@ -24,6 +24,7 @@ Rectangle {
     required property bool isIncoming
     required property bool isEstablished
     required property date establishedTime
+    required property int callDelay
     required property bool isHolding
     required property bool isFinished
     required property bool hasCapabilityJitsi
@@ -41,7 +42,6 @@ Rectangle {
 
     signal clicked
 
-
     states: [
         State {
             when: control.isHolding