diff --git a/src/lib/sip-client.ts b/src/lib/sip-client.ts
index 129a491..2f3e4be 100644
--- a/src/lib/sip-client.ts
+++ b/src/lib/sip-client.ts
@@ -223,10 +223,17 @@ export class SIPClient {
     }
 
     private extractCallerNumber(session: RTCSession): string {
-        // Try P-Asserted-Identity header first (most reliable for real caller ID)
         try {
             const request = session.direction === 'incoming' ? (session as any)._request : null;
             if (request) {
+                // Ozonetel sends the real caller number in X-CALLERNO header
+                const xCallerNo = request.getHeader('X-CALLERNO');
+                if (xCallerNo) {
+                    // Remove leading 0s or country code prefix (00919... → 919...)
+                    const cleaned = xCallerNo.replace(/^0+/, '');
+                    return cleaned;
+                }
+
                 // Check P-Asserted-Identity
                 const pai = request.getHeader('P-Asserted-Identity');
                 if (pai) {
@@ -241,11 +248,11 @@ export class SIPClient {
                     if (match) return match[1];
                 }
 
-                // Check X-Original-CallerID (custom header some PBX systems use)
+                // Check X-Original-CallerID
                 const xCid = request.getHeader('X-Original-CallerID');
                 if (xCid) return xCid;
 
-                // Check From header display name (sometimes contains the real number)
+                // Check From header display name
                 const fromDisplay = request.from?.display_name;
                 if (fromDisplay && /^\+?\d{7,}$/.test(fromDisplay)) {
                     return fromDisplay;
diff --git a/src/providers/sip-provider.tsx b/src/providers/sip-provider.tsx
index 8c561ce..2995368 100644
--- a/src/providers/sip-provider.tsx
+++ b/src/providers/sip-provider.tsx
@@ -1,4 +1,4 @@
-import { createContext, useContext, useEffect, useRef, useState, type PropsWithChildren } from 'react';
+import { createContext, useContext, useEffect, useState, type PropsWithChildren } from 'react';
 import { useSipPhone } from '@/hooks/use-sip-phone';
 
 type SipContextType = ReturnType<typeof useSipPhone> & {
@@ -8,22 +8,20 @@ type SipContextType = ReturnType<typeof useSipPhone> & {
 
 const SipContext = createContext<SipContextType | null>(null);
 
+// Module-level flag — survives React StrictMode double-mount
+let sipConnectedGlobal = false;
+
 export const SipProvider = ({ children }: PropsWithChildren) => {
     const sipPhone = useSipPhone();
-    const hasConnected = useRef(false);
     const [ozonetelStatus, setOzonetelStatus] = useState<'idle' | 'logging-in' | 'logged-in' | 'error'>('idle');
     // eslint-disable-next-line @typescript-eslint/no-unused-vars
     const [ozonetelError, _setOzonetelError] = useState<string | null>(null);
 
-    // Auto-connect SIP on mount — only WebSocket/SIP registration
-    // Ozonetel agent login is handled by the sidecar during auth, NOT here
+    // Auto-connect SIP on mount — module-level guard prevents duplicate connections
     useEffect(() => {
-        if (!hasConnected.current) {
-            hasConnected.current = true;
+        if (!sipConnectedGlobal) {
+            sipConnectedGlobal = true;
             sipPhone.connect();
-
-            // Ozonetel status tracks whether the sidecar handled agent login
-            // We assume logged-in if SIP connects (sidecar handles the REST login)
             setOzonetelStatus('logged-in');
         }
         // eslint-disable-next-line react-hooks/exhaustive-deps