diff --git a/src/org/openlcb/implementations/MemoryConfigurationService.java b/src/org/openlcb/implementations/MemoryConfigurationService.java
index 3ca8f116..768f0f73 100644
--- a/src/org/openlcb/implementations/MemoryConfigurationService.java
+++ b/src/org/openlcb/implementations/MemoryConfigurationService.java
@@ -527,6 +527,14 @@ public void run() {
         retryTimer.schedule(tt, timeout);
     }
     
+    static int computeTimeout(int flags) {
+        int timeoutExp = flags & 0x0F;
+        if (timeoutExp == 0) {
+            return 3000;  // no timeout specified, 3 seconds is default
+        }
+        return (1 << timeoutExp) * 1000; // 2^N seconds to msec
+    }
+
     // invoked when retryTimer times out
     private void timeoutRetry(final McsRequestMemo memo) {
         logger.log(Level.FINE, "timeoutRetry entry");
@@ -556,8 +564,7 @@ public void handleSuccess(int flags) {
                         ((flags & DatagramService.FLAG_REPLY_PENDING) != 0)) {
                     // Leave the memo in the pending, will wait for reply datagram.
                     logger.fine("rcvd RequestWithReplyDatagram with flags "+flags);
-                    int timeout = 1 << (flags & 0x0F) * 1000; // to msec
-                    if ((flags & 0x0F) == 0) timeout = 3000;  // no timeout specified, 3 seconds is default
+                    int timeout = computeTimeout(flags);
                     logger.fine("            and timeout  "+timeout+", restarting");
                     restartTimeout(memo, timeout);
                     return;
diff --git a/test/org/openlcb/implementations/MemoryConfigurationServiceTest.java b/test/org/openlcb/implementations/MemoryConfigurationServiceTest.java
index f8f28e49..209ff54c 100644
--- a/test/org/openlcb/implementations/MemoryConfigurationServiceTest.java
+++ b/test/org/openlcb/implementations/MemoryConfigurationServiceTest.java
@@ -702,4 +702,20 @@ public void handleAddrSpaceData(NodeID dest, int space, long hiAddress, long low
                 
     }
 
+    @Test
+    public void testComputeTimeout() {
+        // Exponent 0: default 3000 ms
+        Assert.assertEquals(3000, MemoryConfigurationService.computeTimeout(0));
+        Assert.assertEquals(3000, MemoryConfigurationService.computeTimeout(DatagramService.FLAG_REPLY_PENDING | 0));
+
+        // Exponents 1..4: 2^N seconds in milliseconds
+        Assert.assertEquals(2000, MemoryConfigurationService.computeTimeout(DatagramService.FLAG_REPLY_PENDING | 1));
+        Assert.assertEquals(4000, MemoryConfigurationService.computeTimeout(DatagramService.FLAG_REPLY_PENDING | 2));
+        Assert.assertEquals(8000, MemoryConfigurationService.computeTimeout(DatagramService.FLAG_REPLY_PENDING | 3));
+        Assert.assertEquals(16000, MemoryConfigurationService.computeTimeout(DatagramService.FLAG_REPLY_PENDING | 4));
+
+        // Max exponent 15: 2^15 seconds in milliseconds
+        Assert.assertEquals(32768000, MemoryConfigurationService.computeTimeout(DatagramService.FLAG_REPLY_PENDING | 15));
+    }
+
 }