diff --git a/common/sign.h b/common/sign.h
index e7b8941..5d9b977 100644
--- a/common/sign.h
+++ b/common/sign.h
@@ -86,13 +86,14 @@ public:
 
     static quint32 magic();
     static bool packetGuid(const uchar *pkt, int pktLen, uint *guid);
+
     static const quint32 kMaxGuid = 0x00ffffff;
+    static const quint8 kTypeLenTtagPlaceholder = 0x22;
+    static const quint8 kTypeLenTtag = 0x23;
 private:
     static const quint32 kSignMagic = 0x1d10c0da; // coda! (unicode - 0x1d10c)
     static const quint8 kTypeLenEnd = 0x00;
     static const quint8 kTypeLenGuid = 0x61;
-    static const quint8 kTypeLenTtagPlaceholder = 0x22;
-    static const quint8 kTypeLenTtag = 0x23;
     OstProto::Sign data;
 };
 
diff --git a/server/packetsequence.h b/server/packetsequence.h
index 903fc1e..a4c8a88 100644
--- a/server/packetsequence.h
+++ b/server/packetsequence.h
@@ -79,6 +79,7 @@ public:
     int repeatCount_;
     int repeatSize_;
     long usecDelay_;
+    qulonglong ttagPktInterval_{0}; // ttag pkt once every X packets
     StreamStats streamStatsMeta_;
 
 private:
diff --git a/server/pcaptxthread.cpp b/server/pcaptxthread.cpp
index a5d5e93..3946352 100644
--- a/server/pcaptxthread.cpp
+++ b/server/pcaptxthread.cpp
@@ -19,6 +19,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 #include "pcaptxthread.h"
 
+#include "sign.h"
 #include "statstuple.h"
 #include "timestamp.h"
 
@@ -132,6 +133,8 @@ void PcapTxThread::loopNextPacketSet(qint64 size, qint64 repeats,
     currentPacketSequence_->repeatCount_ = repeats;
     currentPacketSequence_->usecDelay_ = repeatDelaySec * long(1e6)
                                             + repeatDelayNsec/1000;
+    currentPacketSequence_->ttagPktInterval_ =
+            kTtagPktInterval*1e6/currentPacketSequence_->usecDelay_;
 
     repeatSequenceStart_ = packetSequenceList_.size();
     repeatSize_ = size;
@@ -195,6 +198,8 @@ bool PcapTxThread::appendToPacketList(long sec, long nsec,
             start->usecDelay_ = 0;
             start->repeatSize_ =
                     packetSequenceList_.size() - repeatSequenceStart_;
+            start->ttagPktInterval_ = kTtagPktInterval*1e6
+                                        /currentPacketSequence_->usecDelay_;
         }
 
         repeatSize_ = 0;
@@ -270,9 +275,10 @@ void PcapTxThread::run()
                 packetSequenceList_.at(i)->repeatCount_,
                 packetSequenceList_.at(i)->repeatSize_,
                 packetSequenceList_.at(i)->usecDelay_);
-        qDebug("sendQ[%d]: pkts = %ld, usecDuration = %ld", i,
+        qDebug("sendQ[%d]: pkts = %ld, usecDuration = %ld, ttagPktIntvl = %llu", i,
                 packetSequenceList_.at(i)->packets_,
-                packetSequenceList_.at(i)->usecDuration_);
+                packetSequenceList_.at(i)->usecDuration_,
+                packetSequenceList_.at(i)->ttagPktInterval_);
     }
 
     lastStats_ = *stats_; // used for stream stats
@@ -309,11 +315,11 @@ _restart:
                         ret = -2;
                 } else {
                     ret = sendQueueTransmit(handle_, seq->sendQueue_,
-                            overHead, kSyncTransmit);
+                            seq->ttagPktInterval_, overHead, kSyncTransmit);
                 }
 #else
                 ret = sendQueueTransmit(handle_, seq->sendQueue_,
-                            overHead, kSyncTransmit);
+                            seq->ttagPktInterval_, overHead, kSyncTransmit);
 #endif
 
                 if (ret >= 0) {
@@ -402,8 +408,8 @@ double PcapTxThread::lastTxDuration()
     return lastTxDuration_;
 }
 
-int PcapTxThread::sendQueueTransmit(pcap_t *p,
-        pcap_send_queue *queue, long &overHead, int sync)
+int PcapTxThread::sendQueueTransmit(pcap_t *p, pcap_send_queue *queue,
+        quint64 ttagPktInterval, long &overHead, int sync)
 {
     TimeStamp ovrStart, ovrEnd;
     struct timeval ts;
@@ -415,6 +421,14 @@ int PcapTxThread::sendQueueTransmit(pcap_t *p,
     while((char*) hdr < end) {
         uchar *pkt = (uchar*)hdr + sizeof(*hdr);
         int pktLen = hdr->caplen;
+        bool ttagPkt = false;
+
+        // Time for a T-Tag packet?
+        if (ttagPktInterval && ((stats_->pkts % ttagPktInterval) == 0)) {
+            ttagPkt = true;
+            // FIXME: fixup cksum(s)
+            *(pkt+pktLen-5) = SignProtocol::kTypeLenTtag;
+        }
 
         if (sync) {
             long usec = (hdr->ts.tv_sec - ts.tv_sec) * 1000000 +
@@ -440,6 +454,11 @@ int PcapTxThread::sendQueueTransmit(pcap_t *p,
         stats_->pkts++;
         stats_->bytes += pktLen;
 
+        // Revert T-Tag packet changes
+        if (ttagPkt) {
+            *(pkt+pktLen-5) = SignProtocol::kTypeLenTtagPlaceholder;
+        }
+
         // Step to the next packet in the buffer
         hdr = (struct pcap_pkthdr*) (pkt + pktLen);
         pkt = (uchar*) ((uchar*)hdr + sizeof(*hdr)); // FIXME: superfluous?
diff --git a/server/pcaptxthread.h b/server/pcaptxthread.h
index 15cef2b..c3a3f1b 100644
--- a/server/pcaptxthread.h
+++ b/server/pcaptxthread.h
@@ -66,8 +66,8 @@ private:
     };
 
     static void udelay(unsigned long usec);
-    int sendQueueTransmit(pcap_t *p, pcap_send_queue *queue, long &overHead,
-                int sync);
+    int sendQueueTransmit(pcap_t *p, pcap_send_queue *queue,
+            quint64 ttagPktInterval, long &overHead, int sync);
     void updateTxStreamStats();
 
     // Intermediate state variables used while building the packet list
@@ -95,6 +95,8 @@ private:
     StreamStats streamStats_;
 
     double lastTxDuration_{0.0}; // in secs
+
+    const ulong kTtagPktInterval{5}; // T-Tag pkt once every X sec
 };
 
 #endif