Fixed maximum MSU size, it's 273 including SIO.

git-svn-id: http://yate.null.ro/svn/yate/trunk@6278 acf43c95-373e-0410-b603-e72c3f656dc1

conf.d/ysigchan.conf.sample

@@ -550,11 +550,11 @@
 ;  A value of 8 or higher disables load balancing.
 ;
 ; Size represents the maximum MSU size that can be transported on this route.
-; The default vaue is 272 -> maximum MSU size on TDM.
+; The default value is 273 -> maximum MSU size on TDM.
 ; If the route can transport more data, a value up to 4000 should be set to
 ;  avoid SCCP message fragmentation.
 ;
-; Example: route=ITU,2-2-2,100,1,272
+; Example: route=ITU,2-2-2,100,1,273
 ;route=
 
 ; adjacent: string: Build an adjacent route for the SS7 network (A, E and F links)
@@ -565,11 +565,11 @@
 ; The priority is always zero so an adjacent route will always match first.
 ;
 ; Size represents the maximum MSU size that can be transported on this route.
-; The default vaue is 272 -> maximum MSU size on TDM.
+; The default value is 273 -> maximum MSU size on TDM.
 ; If the route can transport more data, a value up to 4000 should be set to
 ;  avoid SCCP message fragmentation
 ;
-; Example: adjacent=ANSI,40-50-60,272
+; Example: adjacent=ANSI,40-50-60,273
 ;adjacent=
 
 ; local: string: Declare a local pointcode for the SS7 network

libs/ysig/layer2.cpp

@@ -77,7 +77,8 @@ SS7MSU::~SS7MSU()
 
 bool SS7MSU::valid() const
 {
-    return (3 < length()) && (length() < 273);
+    // Routing label + data without SIO is between 2 and 272 octets (Q.703 2.3.8)
+    return (3 <= length()) && (length() <= MAX_TDM_MSU_SIZE);
 }
 
 #define CASE_STR(x) case x: return #x

libs/ysig/layer3.cpp

@@ -26,8 +26,6 @@
 
 using namespace TelEngine;
 
-#define MAX_TDM_DATA_SIZE 272
-
 static const TokenDict s_dict_control[] = {
     { "show",    SS7MTP3::Status },
     { "pause",   SS7MTP3::Pause },
@@ -180,7 +178,7 @@ bool SS7Layer3::buildRoutes(const NamedList& params)
 	    continue;
 	unsigned int prio = 0;
 	unsigned int shift = 0;
-	unsigned int maxLength = MAX_TDM_DATA_SIZE;
+	unsigned int maxLength = MAX_TDM_MSU_SIZE;
 	bool local = false;
 	if (ns->name() == YSTRING("local"))
 	    local = true;
@@ -211,10 +209,10 @@ bool SS7Layer3::buildRoutes(const NamedList& params)
 	    if (!(obj = obj->skipNext()) || local)
 		break;
 	    maxLength = obj->get()->toString().toInteger(maxLength);
-	    if (maxLength < MAX_TDM_DATA_SIZE) {
+	    if (maxLength < MAX_TDM_MSU_SIZE) {
 		Debug(this,DebugNote,"MaxDataLength is too small %d. Setting it to %d",
-			maxLength,MAX_TDM_DATA_SIZE);
-		maxLength = MAX_TDM_DATA_SIZE;
+			maxLength,MAX_TDM_MSU_SIZE);
+		maxLength = MAX_TDM_MSU_SIZE;
 	    }
 	} while (false);
 	TelEngine::destruct(route);
@@ -247,12 +245,12 @@ bool SS7Layer3::buildRoutes(const NamedList& params)
 unsigned int SS7Layer3::getRouteMaxLength(SS7PointCode::Type type, unsigned int packedPC)
 {
     if (type == SS7PointCode::Other || (unsigned int)type > YSS7_PCTYPE_COUNT || !packedPC)
-	return MAX_TDM_DATA_SIZE;
+	return MAX_TDM_MSU_SIZE;
     Lock lock(m_routeMutex);
     SS7Route* route = findRoute(type,packedPC);
     if (route)
 	return route->m_maxDataLength;
-    return MAX_TDM_DATA_SIZE;
+    return MAX_TDM_MSU_SIZE;
 }
 
 

libs/ysig/sccp.cpp

@@ -3253,12 +3253,12 @@ void SS7SCCP::getMaxDataLen(const SS7MsgSCCP* msg, const SS7Label& label,
     }
 
     unsigned int maxLen = network()->getRouteMaxLength(m_type,label.dpc().pack(m_type));
-    if (maxLen < 272) {
+    if (maxLen < MAX_TDM_MSU_SIZE) {
 	DDebug(this,DebugInfo,"Received MSU size (%d) lower than maximum TDM!",
 	       maxLen);
-	maxLen = 272;
+	maxLen = MAX_TDM_MSU_SIZE;
     }
-    bool ludtSupport = maxLen > 272; // 272 maximum msu size
+    bool ludtSupport = maxLen > MAX_TDM_MSU_SIZE; // Maximum MSU size (SIO + Label + data)
     maxLen -= (label.length() + 1); // subtract label length and SIO octet
     // Now max length represents the maximum length of SCCP message
     // Adjust maxLen to represent maximum data in the message.

libs/ysig/yatesig.h

@@ -3905,6 +3905,9 @@ private:
  */
 YSIG_API String& operator<<(String& str, const SS7Label& label);
 
+// Maximum size of a MTP2 MSU including SIO + Routing Label + data (Q.703 2.3.8)
+#define MAX_TDM_MSU_SIZE 273
+
 /**
  * A raw data block with a little more understanding about MSU format
  * @short A block of data that holds a Message Signal Unit
@@ -5981,7 +5984,7 @@ public:
      */
     inline SS7Route(unsigned int packed, SS7PointCode::Type type,
 	    unsigned int priority = 0, unsigned int shift = 0,
-	    unsigned int maxDataLength = 272)
+	    unsigned int maxDataLength = MAX_TDM_MSU_SIZE)
 	: Mutex(true,"SS7Route"), m_packed(packed), m_type(type),
 	m_priority(priority), m_shift(shift),m_maxDataLength(maxDataLength),
 	m_state(Unknown),m_buffering(0), m_congCount(0),m_congBytes(0)
@@ -6413,7 +6416,7 @@ public:
      * This method is thread safe
      * @param type Destination point code type
      * @param packedPC The packed point code
-     * @return The maximum data length that can be transported on the route. Maximum msu size (272) if no route to the given point code
+     * @return The maximum data length that can be transported on the route. Maximum msu size (273) if no route to the given point code
      */
     unsigned int getRouteMaxLength(SS7PointCode::Type type, unsigned int packedPC);