diff --git a/resource/c_common/octimer/include/octimer.h b/resource/c_common/octimer/include/octimer.h
index bd13a76a63255bf0d747112c0a70aaf709f4dd39..0a5471088d60e81ad2367d7c108265f3628eeda1 100644
--- a/resource/c_common/octimer/include/octimer.h
+++ b/resource/c_common/octimer/include/octimer.h
@@ -52,7 +52,7 @@ extern "C"
 #define SECS_YR_2000  (946684800L)
 #endif
 
-typedef void(*TimerCallback)();
+typedef void(*TimerCallback)(void *ctx);
 
 /**
  * Calculate time difference.
@@ -82,13 +82,13 @@ time_t getSecondsFromAbsTime(struct tm *tp);
 
 int initThread();
 void *loop(void *threadid);
-time_t registerTimer(const time_t seconds, int *id, TimerCallback cb);
+time_t registerTimer(const time_t seconds, int *id, TimerCallback cb, void *ctx);
 void unregisterTimer(int id);
 
 #else
 
 time_t timeToSecondsFromNow(tmElements_t *t);
-time_t registerTimer(const time_t seconds, int *id, TimerCallback cb);
+time_t registerTimer(const time_t seconds, int *id, TimerCallback cb, void *ctx);
 void unregisterTimer(int id);
 
 
diff --git a/resource/c_common/octimer/src/octimer.c b/resource/c_common/octimer/src/octimer.c
index c4a9285516caf6b0d537a1d401ef8501156cbd07..190106b0318a788c3ec7d9c99b1f1f1f89f33fb9 100644
--- a/resource/c_common/octimer/src/octimer.c
+++ b/resource/c_common/octimer/src/octimer.c
@@ -63,6 +63,7 @@ struct timelist_t
     time_t timeout_seconds;
     time_t timeout_time;
     TimerCallback cb;
+    void *ctx;
 } timeout_list[TIMEOUTS];
 
 time_t timespec_diff(const time_t after, const time_t before)
@@ -154,7 +155,7 @@ time_t getSecondsFromAbsTime(struct tm *tp)
     return delayed_time;
 }
 
-time_t registerTimer(const time_t seconds, int *id, TimerCallback cb)
+time_t registerTimer(const time_t seconds, int *id, TimerCallback cb, void *ctx)
 {
     time_t now, then;
     time_t next;
@@ -189,6 +190,7 @@ time_t registerTimer(const time_t seconds, int *id, TimerCallback cb)
 
     timeout_list[idx].timeout_time = then;
     timeout_list[idx].timeout_seconds = seconds;
+    timeout_list[idx].ctx = ctx;
 
     // printf( "\nbefore timeout_list[idx].cb = %X\n", timeout_list[idx].cb);
     timeout_list[idx].cb = cb;
@@ -238,7 +240,7 @@ void checkTimeout()
                 timeout_list[i].timeout_state = TIMEOUT_UNUSED;
                 if (timeout_list[i].cb)
                 {
-                    timeout_list[i].cb();
+                    timeout_list[i].cb(timeout_list[i].ctx);
                 }
             }
         }
@@ -278,7 +280,7 @@ time_t timeToSecondsFromNow(tmElements_t *t_then)
     return (time_t) (then - t);
 }
 
-time_t registerTimer(const time_t seconds, int *id, TimerCallback cb)
+time_t registerTimer(const time_t seconds, int *id, TimerCallback cb, void *ctx)
 {
     time_t t, then;
     time_t next;
@@ -308,6 +310,7 @@ time_t registerTimer(const time_t seconds, int *id, TimerCallback cb)
 
     timeout_list[idx].timeout_time = then;
     timeout_list[idx].timeout_seconds = seconds;
+    timeout_list[idx].ctx = ctx;
 
     // printf( "\nbefore timeout_list[idx].cb = %X\n", timeout_list[idx].cb);
     timeout_list[idx].cb = cb;
@@ -361,7 +364,7 @@ void checkTimeout()
                 timeout_list[i].timeout_state = TIMEOUT_UNUSED;
                 if (timeout_list[i].cb)
                 {
-                    timeout_list[i].cb();
+                    timeout_list[i].cb(timeout_list[i].ctx);
                 }
             }
         }
diff --git a/resource/csdk/connectivity/src/adapter_util/ca_adapter_net_ssl.c b/resource/csdk/connectivity/src/adapter_util/ca_adapter_net_ssl.c
index 7bcb6013a2adda37711e6fd09abce9f36b52a29a..b43430b5c88ddfb27ec64de823cd05e853bc11e4 100644
--- a/resource/csdk/connectivity/src/adapter_util/ca_adapter_net_ssl.c
+++ b/resource/csdk/connectivity/src/adapter_util/ca_adapter_net_ssl.c
@@ -1581,11 +1581,12 @@ static int InitConfig(mbedtls_ssl_config * conf, int transport, int mode)
 /**
  * Starts DTLS retransmission.
  */
-static void StartRetransmit()
+static void StartRetransmit(void *ctx)
 {
     size_t listIndex = 0;
     size_t listLength = 0;
     SslEndPoint_t *tep = NULL;
+    OC_UNUSED(ctx);
 
     oc_mutex_lock(g_sslContextMutex);
     if (NULL == g_caSslContext)
@@ -1615,7 +1616,7 @@ static void StartRetransmit()
             if (MBEDTLS_ERR_SSL_CONN_EOF != ret)
             {
                 //start new timer
-                registerTimer(RETRANSMISSION_TIME, &g_caSslContext->timerId, StartRetransmit);
+                registerTimer(RETRANSMISSION_TIME, &g_caSslContext->timerId, StartRetransmit, NULL);
                 //unlock & return
                 if (!checkSslOperation(tep,
                                        ret,
@@ -1629,7 +1630,7 @@ static void StartRetransmit()
         }
     }
     //start new timer
-    registerTimer(RETRANSMISSION_TIME, &g_caSslContext->timerId, StartRetransmit);
+    registerTimer(RETRANSMISSION_TIME, &g_caSslContext->timerId, StartRetransmit, NULL);
     oc_mutex_unlock(g_sslContextMutex);
 }
 #endif
@@ -1774,7 +1775,7 @@ CAResult_t CAinitSslAdapter()
 
    oc_mutex_unlock(g_sslContextMutex);
 #ifdef __WITH_DTLS__
-    StartRetransmit();
+    StartRetransmit(NULL);
 #endif
 
     OIC_LOG_V(DEBUG, NET_SSL_TAG, "Out %s", __func__);
diff --git a/resource/csdk/stack/src/oicgroup.c b/resource/csdk/stack/src/oicgroup.c
index 49dcab4ddc9e9503e976326a48699ab31b1ef251..836166cbe92fe2c01d86a57592e08b6e0f68aeee 100755
--- a/resource/csdk/stack/src/oicgroup.c
+++ b/resource/csdk/stack/src/oicgroup.c
@@ -1020,8 +1020,9 @@ OCStackResult DoAction(OCResource* resource, OCActionSet* actionset,
     return result;
 }
 
-void DoScheduledGroupAction()
+void DoScheduledGroupAction(void *ctx)
 {
+    OC_UNUSED(ctx);
     OIC_LOG(INFO, TAG, "DoScheduledGroupAction Entering...");
     ScheduledResourceInfo* info = GetScheduledResource(g_scheduleResourceList);
 
@@ -1073,7 +1074,8 @@ void DoScheduledGroupAction()
 
                 schedule->time = registerTimer(info->actionset->timesteps,
                         &schedule->timer_id,
-                        &DoScheduledGroupAction);
+                        &DoScheduledGroupAction,
+                        NULL);
 
                 OIC_LOG(INFO, TAG, "Reregistration.");
                 oc_mutex_unlock(g_scheduledResourceLock);
@@ -1292,7 +1294,8 @@ OCStackResult BuildCollectionGroupActionCBORResponse(
                                 oc_mutex_lock(g_scheduledResourceLock);
                                 schedule->time = registerTimer(delay,
                                         &schedule->timer_id,
-                                        &DoScheduledGroupAction);
+                                        &DoScheduledGroupAction,
+                                        NULL);
                                 oc_mutex_unlock(g_scheduledResourceLock);
                                 AddScheduledResource(&g_scheduleResourceList,
                                         schedule);