diff --git a/SSU.cpp b/SSU.cpp
index d2efc892..3932b37f 100644
--- a/SSU.cpp
+++ b/SSU.cpp
@@ -733,19 +733,40 @@ namespace ssu
 		uint16_t port = *(uint16_t *)buf; // use it as is
 		buf += 2; // port
 		uint8_t * introKey = buf;
-		if (port)
+		if (port && !address)
 		{
-			LogPrint ("SSU peer test. We are Charlie");
-			Send (PAYLOAD_TYPE_PEER_TEST, buf1, len); // back to Bob
-			if (address)
-				SendPeerTest (nonce, be32toh (*(uint32_t *)address), be16toh (port), introKey); // to Alice
+			LogPrint ("Address of ", size, " bytes not supported");	
+			return;
+		}	
+		if (m_PeerTestNonces.count (nonce) > 0)
+		{
+			// existing test
+			if (port)
+			{
+				LogPrint ("SSU peer test from Charlie. We are Bob");
+				// TODO:  back to Alice
+			}
 			else
-				LogPrint ("Address of ", size, " bytes not supported");	
+			{
+				LogPrint ("SSU peer test from Alice. We are Charlie");
+				SendPeerTest (nonce, be32toh (*(uint32_t *)address), be16toh (port), introKey); // to Alice
+			}
 		}
 		else
 		{
-			LogPrint ("SSU peer test. We are Bob");
-			// TODO:
+			// new test
+			m_PeerTestNonces.insert (nonce);
+			if (port)
+			{
+				LogPrint ("SSU peer test from Bob. We are Charlie");
+				Send (PAYLOAD_TYPE_PEER_TEST, buf1, len); // back to Bob
+				SendPeerTest (nonce, be32toh (*(uint32_t *)address), be16toh (port), introKey); // to Alice
+			}
+			else
+			{
+				LogPrint ("SSU peer test from Alice. We are Bob");
+				// TODO: find Charlie
+			}
 		}	
 	}
 	
diff --git a/SSU.h b/SSU.h
index 03e889ea..334fd710 100644
--- a/SSU.h
+++ b/SSU.h
@@ -4,6 +4,7 @@
 #include <inttypes.h>
 #include <map>
 #include <list>
+#include <set>
 #include <boost/asio.hpp>
 #include <cryptopp/modes.h>
 #include <cryptopp/aes.h>
@@ -131,6 +132,7 @@ namespace ssu
 			bool m_PeerTest;
 			SessionState m_State;
 			uint32_t m_RelayTag;	
+			std::set<uint32_t> m_PeerTestNonces;
 			CryptoPP::CBC_Mode<CryptoPP::AES>::Encryption m_Encryption;	
 			CryptoPP::CBC_Mode<CryptoPP::AES>::Decryption m_Decryption;	
 			uint8_t m_SessionKey[32], m_MacKey[32];