diff --git a/libsrc/meshing/meshclass.cpp b/libsrc/meshing/meshclass.cpp
index a89a6ff3..d49e37a4 100644
--- a/libsrc/meshing/meshclass.cpp
+++ b/libsrc/meshing/meshclass.cpp
@@ -44,6 +44,7 @@ namespace netgen
     cd2names.SetSize(0);
 
 #ifdef PARALLEL
+    this->comm = MPI_COMM_WORLD;
     paralleltop = new ParallelMeshTopology (*this);
 #endif
   }
diff --git a/libsrc/meshing/meshclass.hpp b/libsrc/meshing/meshclass.hpp
index 1befedce..7b6ac3cd 100644
--- a/libsrc/meshing/meshclass.hpp
+++ b/libsrc/meshing/meshclass.hpp
@@ -32,6 +32,11 @@ namespace netgen
     /// point coordinates
     T_POINTS points;
 
+#ifdef PARALLEL
+    // The communicator for this mesh. (more or less dummy for now!)  
+    MPI_Comm comm;
+#endif
+    
     /// line-segments at edges
     Array<Segment, 0, size_t> segments;
     /// surface elements, 2d-inner elements
diff --git a/libsrc/meshing/parallelmesh.cpp b/libsrc/meshing/parallelmesh.cpp
index 50f64c1c..f574f1f6 100644
--- a/libsrc/meshing/parallelmesh.cpp
+++ b/libsrc/meshing/parallelmesh.cpp
@@ -35,53 +35,25 @@ namespace netgen
 
   void Mesh :: SendRecvMesh ()
   {
+    int id, np;
+    MPI_Comm_rank(this->comm, &id);
+    MPI_Comm_size(this->comm, &np);
+
+    if (np == 1) {
+      throw NgException("SendRecvMesh called, but only one rank in communicator!!");
+    }
+    
     if (id == 0)
       PrintMessage (1, "Send/Receive mesh");
 
-    {
-      // distribute global information
-      int nelglob, nseglob, nvglob;
-      if (id == 0)
-	{
-	  paralleltop -> SetNV (GetNV());
-	  paralleltop -> SetNE (GetNE());
-	  paralleltop -> SetNSegm (GetNSeg());
-	  paralleltop -> SetNSE (GetNSE());
-
-	  nelglob = GetNE();
-	  nseglob = GetNSE();
-	  nvglob = GetNV();
-	}
-      
-      MyMPI_Bcast (dimension);
-      MyMPI_Bcast (nelglob);
-      MyMPI_Bcast (nseglob);
-      MyMPI_Bcast (nvglob);
-    }
-
-
-
-    {
-      // distribute number of local elements
-      if (id == 0)
-	{
-	  Array<int> num_els_on_proc(ntasks);
-	  num_els_on_proc = 0;
-	  for (ElementIndex ei = 0; ei < GetNE(); ei++)
-	    num_els_on_proc[(*this)[ei].GetPartition()]++;
-	  
-	  MPI_Scatter (&num_els_on_proc[0], 1, MPI_INT,
-		       MPI_IN_PLACE, -1, MPI_INT, 0, MPI_COMM_WORLD);
-	}
-      else
-	{
-	  int nelloc;
-	  MPI_Scatter (NULL, 0, MPI_INT,
-		       &nelloc, 1, MPI_INT, 0, MPI_COMM_WORLD);
-	  
-	  paralleltop -> SetNE (nelloc);
-	}
-    }
+    // Why is this here??
+    if (id == 0)
+      {
+	paralleltop -> SetNV (GetNV());
+	paralleltop -> SetNE (GetNE());
+	paralleltop -> SetNSegm (GetNSeg());
+	paralleltop -> SetNSE (GetNSE());
+      }
 
     if (id == 0)
       SendMesh ();
@@ -101,18 +73,29 @@ namespace netgen
   {
     Array<MPI_Request> sendrequests;
 
-    PrintMessage ( 3, "Sending vertices");
+    int dim = GetDimension();
+    MyMPI_Bcast(dim);
 
+    
+    const_cast<MeshTopology&>(GetTopology()).Update();
+    
+    PrintMessage ( 3, "Sending nr of elements");
+    
+    MPI_Comm comm = this->comm;
 
     Array<int> num_els_on_proc(ntasks);
     num_els_on_proc = 0;
     for (ElementIndex ei = 0; ei < GetNE(); ei++)
       num_els_on_proc[(*this)[ei].GetPartition()]++;
 
+    MPI_Scatter (&num_els_on_proc[0], 1, MPI_INT,
+		 MPI_IN_PLACE, -1, MPI_INT, 0, comm);
+
     TABLE<ElementIndex> els_of_proc (num_els_on_proc);
     for (ElementIndex ei = 0; ei < GetNE(); ei++)
       els_of_proc.Add ( (*this)[ei].GetPartition(), ei);
 
+    PrintMessage ( 3, "Building vertex/proc mapping");
 
     Array<int> num_sels_on_proc(ntasks);
     num_sels_on_proc = 0;
@@ -133,132 +116,160 @@ namespace netgen
       segs_of_proc.Add ( (*this)[ei].GetPartition(), ei);
 
 
+    /**
+            ----- STRATEGY FOR PERIODIC MESHES -----
 
+       Whenever two vertices are identified by periodicity, any proc 
+       that gets one of the vertices actually gets both of them.
+       This has to be transitive, that is, if
+       a <-> b and  b <-> c,
+       then any proc that has vertex a also has vertices b and c!
 
+       Surfaceelements and Segments that are identified by
+       periodicity are treated the same way.
+       
+       We need to duplicate these so we have containers to
+       hold the edges/facets. Afaik, a mesh cannot have nodes 
+       that are not part of some sort of element.
+
+     **/
+
+    /** First, we build tables for vertex identification. **/
+    Array<INDEX_2> per_pairs;
+    Array<INDEX_2> pp2;
+    auto & idents = GetIdentifications();
+    bool has_periodic = false; 
+    for (int idnr = 1; idnr < idents.GetMaxNr()+1; idnr++)
+      {
+	if(idents.GetType(idnr)!=Identifications::PERIODIC) continue;
+	has_periodic = true;
+	idents.GetPairs(idnr, pp2);
+	per_pairs.Append(pp2);
+      }
+    Array<int, PointIndex::BASE> npvs(GetNV());
+    npvs = 0;
+    for (int k = 0; k < per_pairs.Size(); k++) {
+      npvs[per_pairs[k].I1()]++;
+      npvs[per_pairs[k].I2()]++;
+    }
+
+    /** for each vertex, gives us all identified vertices **/
+    TABLE<PointIndex, PointIndex::BASE> per_verts(npvs);
+    for (int k = 0; k < per_pairs.Size(); k++) {
+      per_verts.Add(per_pairs[k].I1(), per_pairs[k].I2());
+      per_verts.Add(per_pairs[k].I2(), per_pairs[k].I1());
+    }
+    for (int k = PointIndex::BASE; k < GetNV()+PointIndex::BASE; k++) {
+      BubbleSort(per_verts[k]);
+    }
+
+    /** The same table as per_verts, but TRANSITIVE!! **/
+    auto iterate_per_verts_trans = [&](auto f){
+      Array<int> allvs;
+      for (int k = PointIndex::BASE; k < GetNV()+PointIndex::BASE; k++)
+	{
+	  allvs.SetSize(0);
+	  allvs.Append(per_verts[k]);
+	  bool changed = true;
+	  while(changed) {
+	    changed = false;
+	    for (int j = 0; j<allvs.Size(); j++)
+	      {
+		auto pervs2 = per_verts[allvs[j]];
+		for (int l = 0; l < pervs2.Size(); l++)
+		  {
+		    auto addv = pervs2[l];
+		    if (allvs.Contains(addv) || addv==k) continue;
+		    changed = true;
+		    allvs.Append(addv);
+		  }
+	      }
+	  }
+	  f(k, allvs);
+	}
+    };
+    iterate_per_verts_trans([&](auto k, auto & allvs) {
+	npvs[k] = allvs.Size();
+      });
+    TABLE<PointIndex, PointIndex::BASE> per_verts_trans(npvs);
+    iterate_per_verts_trans([&](auto k, auto & allvs) {
+	for (int j = 0; j<allvs.Size(); j++)
+	  per_verts_trans.Add(k, allvs[j]);
+      });
+    for (int k = PointIndex::BASE; k < GetNV()+PointIndex::BASE; k++) {
+      BubbleSort(per_verts_trans[k]);
+    }
+
+    /** Now we build the vertex-data to send to the workers. **/
     Array<int, PointIndex::BASE> vert_flag (GetNV());
     Array<int, PointIndex::BASE> num_procs_on_vert (GetNV());
     Array<int> num_verts_on_proc (ntasks);
-
     num_verts_on_proc = 0;
     num_procs_on_vert = 0;
-    vert_flag = -1;
-
-
-    for (int dest = 1; dest < ntasks; dest++)
-      {
-	FlatArray<ElementIndex> els = els_of_proc[dest];
-	for (int hi = 0; hi < els.Size(); hi++)
-	  {
-	    const Element & el = (*this) [ els[hi] ];
-	    for (int i = 0; i < el.GetNP(); i++)
-	      {
-		PointIndex epi = el[i]; 
-		if (vert_flag[epi] < dest)
-		  {
-		    vert_flag[epi] = dest;
-
-		    num_verts_on_proc[dest]++;
-		    num_procs_on_vert[epi]++;
-
-		    paralleltop -> SetDistantPNum (dest, epi); 
-		  }
-	      }
-	  }
-
-
-	FlatArray<SurfaceElementIndex> sels = sels_of_proc[dest];
-	for (int hi = 0; hi < sels.Size(); hi++)
-	  {
-	    const Element2d & el = (*this) [ sels[hi] ];
-	    for (int i = 0; i < el.GetNP(); i++)
-	      {
-		PointIndex epi = el[i]; 
-		if (vert_flag[epi] < dest)
-		  {
-		    vert_flag[epi] = dest;
-
-		    num_verts_on_proc[dest]++;
-		    num_procs_on_vert[epi]++;
-
-		    paralleltop -> SetDistantPNum (dest, epi);
-		  }
-	      }
-	  }
-
-	FlatArray<SegmentIndex> segs = segs_of_proc[dest];
-	for (int hi = 0; hi < segs.Size(); hi++)
-	  {
-	    const Segment & el = (*this) [segs[hi]];
-	    for (int i = 0; i < 2; i++)
-	      {
-		PointIndex epi = el[i]; 
-		if (vert_flag[epi] < dest)
-		  {
-		    vert_flag[epi] = dest;
-
-		    num_verts_on_proc[dest]++;
-		    num_procs_on_vert[epi]++;
-
-		    paralleltop -> SetDistantPNum (dest, epi);
-		  }
-	      }
-	  }
-      }
-
+    auto iterate_vertices = [&](auto f) {
+      vert_flag = -1;
+      for (int dest = 1; dest < ntasks; dest++)
+	{
+	  FlatArray<ElementIndex> els = els_of_proc[dest];
+	  for (int hi = 0; hi < els.Size(); hi++)
+	    {
+	      const Element & el = (*this) [ els[hi] ];
+	      for (int i = 0; i < el.GetNP(); i++)
+		f(el[i], dest);
+	    }
+	  FlatArray<SurfaceElementIndex> sels = sels_of_proc[dest];
+	  for (int hi = 0; hi < sels.Size(); hi++)
+	    {
+	      const Element2d & el = (*this) [ sels[hi] ];
+	      for (int i = 0; i < el.GetNP(); i++)
+		f(el[i], dest);
+	    }
+	  FlatArray<SegmentIndex> segs = segs_of_proc[dest];
+	  for (int hi = 0; hi < segs.Size(); hi++)
+	    {
+	      const Segment & el = (*this) [segs[hi]];
+	      for (int i = 0; i < 2; i++)
+		f(el[i], dest);
+	    }
+	}
+    };
+    /** count vertices per proc and procs per vertex **/
+    iterate_vertices([&](auto vertex, auto dest){
+	auto countit = [&] (auto vertex, auto dest) {
+	  if (vert_flag[vertex] < dest)
+	    {
+	      vert_flag[vertex] = dest;
+	      num_verts_on_proc[dest]++;
+	      num_procs_on_vert[vertex]++;
+	      GetParallelTopology().SetDistantPNum (dest, vertex); 
+	    }
+	};
+	countit(vertex, dest);
+	auto pers = per_verts_trans[vertex];
+	for(int j = 0; j < pers.Size(); j++)
+	  countit(pers[j], dest);
+      });
     TABLE<PointIndex> verts_of_proc (num_verts_on_proc);
     TABLE<int, PointIndex::BASE> procs_of_vert (num_procs_on_vert);
     TABLE<int, PointIndex::BASE> loc_num_of_vert (num_procs_on_vert);
-
-    vert_flag = -1;
-    for (int dest = 1; dest < ntasks; dest++)
-      {
-	FlatArray<ElementIndex> els = els_of_proc[dest];
-	for (int hi = 0; hi < els.Size(); hi++)
-	  {
-	    const Element & el = (*this) [ els[hi] ];
-	    for (int i = 0; i < el.GetNP(); i++)
-	      {
-		PointIndex epi = el[i];
-		if (vert_flag[epi] < dest)
-		  {
-		    vert_flag[epi] = dest;
-		    procs_of_vert.Add (epi, dest);
-		  }
-	      }
-	  }
-
-	FlatArray<SurfaceElementIndex> sels = sels_of_proc[dest];
-	for (int hi = 0; hi < sels.Size(); hi++)
-	  {
-	    const Element2d & el = (*this) [ sels[hi] ];
-	    for (int i = 0; i < el.GetNP(); i++)
-	      {
-		PointIndex epi = el[i];
-		if (vert_flag[epi] < dest)
-		  {
-		    vert_flag[epi] = dest;
-		    procs_of_vert.Add (epi, dest);
-		  }
-	      }
-	  }
-
-	FlatArray<SegmentIndex> segs = segs_of_proc[dest];
-	for (int hi = 0; hi < segs.Size(); hi++)
-	  {
-	    const Segment & el = (*this) [ segs[hi] ];
-	    for (int i = 0; i < 2; i++)
-	      {
-		PointIndex epi = el[i];
-		if (vert_flag[epi] < dest)
-		  {
-		    vert_flag[epi] = dest;
-		    procs_of_vert.Add (epi, dest);
-		  }
-	      }
-	  }
-
-      }
-
+    /** Write vertex/proc mappingfs to tables **/
+    iterate_vertices([&](auto vertex, auto dest) {
+	auto addit = [&] (auto vertex, auto dest) {
+	  if (vert_flag[vertex] < dest)
+	    {
+	      vert_flag[vertex] = dest;
+	      procs_of_vert.Add (vertex, dest);
+	    }
+	};
+	addit(vertex, dest);
+	auto pers = per_verts_trans[vertex];
+	for(int j = 0; j < pers.Size(); j++)
+	  addit(pers[j], dest);
+      });
+    /** 
+	local vertex numbers on distant procs 
+	(I think this was only used for debugging??) 
+    **/
     for (int vert = 1; vert <= GetNP(); vert++ )
       {
 	FlatArray<int> procs = procs_of_vert[vert];
@@ -269,6 +280,7 @@ namespace netgen
 	    loc_num_of_vert.Add (vert, verts_of_proc[dest].Size());
 	  }
       }
+    PrintMessage ( 3, "Sending Vertices - vertices");
 
     for (int dest = 1; dest < ntasks; dest++)
       {
@@ -296,6 +308,70 @@ namespace netgen
     Array<int> num_distpnums(ntasks);
     num_distpnums = 0;
 
+
+    /**
+       Next, we send the identifications themselfs.
+       
+       Info about periodic identifications sent to each proc is an array of
+       integers.
+       - maxidentnr
+       - type for each identification
+       - nr of pairs for each identification (each pair is local!)
+       - pairs for each periodic ident (global numbers)
+    **/
+    PrintMessage ( 3, "Sending Vertices - identifications");
+    int maxidentnr = idents.GetMaxNr();
+    Array<int> ppd_sizes(ntasks);
+    ppd_sizes = 1 + 2*maxidentnr;
+    for (int idnr = 1; idnr < idents.GetMaxNr()+1; idnr++)
+      {
+	if(idents.GetType(idnr)!=Identifications::PERIODIC) continue;
+	idents.GetPairs(idnr, pp2);
+	for(int j = 0; j<pp2.Size(); j++)
+	  {
+	    INDEX_2 & pair = pp2[j];
+	    // both are on same procs!
+	    auto ps = procs_of_vert[pair.I1()];
+	    for (int l = 0; l < ps.Size(); l++)
+	      {
+		ppd_sizes[ps[l]] += 2;
+	      }
+	  }
+      }
+    TABLE<int> pp_data(ppd_sizes);
+    for(int dest = 0; dest < ntasks; dest++)
+      pp_data.Add(dest, maxidentnr);
+    for (int dest = 0; dest < ntasks; dest++)
+      {
+	for (int idnr = 1; idnr < idents.GetMaxNr()+1; idnr++)
+	  pp_data.Add(dest, idents.GetType(idnr));
+	for (int idnr = 1; idnr < idents.GetMaxNr()+1; idnr++)
+	  pp_data.Add(dest, 0);
+      }
+    for (int idnr = 1; idnr < idents.GetMaxNr()+1; idnr++)
+      {
+	if(idents.GetType(idnr)!=Identifications::PERIODIC) continue;
+	idents.GetPairs(idnr, pp2);
+	for(int j = 0; j<pp2.Size(); j++)
+	  {
+	    INDEX_2 & pair = pp2[j];
+	    auto ps = procs_of_vert[pair.I1()];
+	    for (int l = 0; l < ps.Size(); l++)
+	      {
+		auto p = ps[l];
+		pp_data[p][maxidentnr + idnr]++;
+		pp_data.Add(p, pair.I1());
+		pp_data.Add(p, pair.I2());
+	      }
+	  }
+      }
+    Array<MPI_Request> req_per;
+    for(int dest = 1; dest < ntasks; dest++)
+      req_per.Append(MyMPI_ISend(pp_data[dest], dest, MPI_TAG_MESH+1));
+    MPI_Waitall(req_per.Size(), &req_per[0], MPI_STATUS_IGNORE);
+
+    PrintMessage ( 3, "Sending Vertices - distprocs");
+    
     for (int vert = 1; vert <= GetNP(); vert++)
       {
 	FlatArray<int> procs = procs_of_vert[vert];
@@ -368,161 +444,240 @@ namespace netgen
     for (int dest = 1; dest < ntasks; dest++)
       sendrequests.Append (MyMPI_ISend (fddata, dest, MPI_TAG_MESH+3));
 
+    /** Surface Elements **/
+
     PrintMessage ( 3, "Sending Surface elements" );
-  
-    Array <int> nlocsel(ntasks), bufsize(ntasks); 
+    // build sel-identification
+    size_t nse = GetNSE();
+    Array<SurfaceElementIndex> ided_sel(nse);
+    ided_sel = -1;
+    bool has_ided_sels = false;
+    if(GetNE() && has_periodic) //we can only have identified surf-els if we have vol-els (right?)
+      {
+	Array<SurfaceElementIndex, 0> os1, os2;
+	for(SurfaceElementIndex sei = 0; sei < GetNSE(); sei++)
+	  {
+	    if(ided_sel[sei]!=-1) continue;
+	    const Element2d & sel = (*this)[sei];
+	    FlatArray<const PointIndex> points = sel.PNums();
+	    auto ided1 = per_verts[points[0]];
+	    os1.SetSize(0);
+	    for (int j = 0; j < ided1.Size(); j++)
+	      os1.Append(GetTopology().GetVertexSurfaceElements(ided1[j]));
+	    for (int j = 1; j < points.Size(); j++)
+	      {
+		os2.SetSize(0);
+		auto p2 = points[j];
+		auto ided2 = per_verts[p2];
+		for (int l = 0; l < ided2.Size(); l++)
+		  os2.Append(GetTopology().GetVertexSurfaceElements(ided2[l]));
+		for (int m = 0; m<os1.Size(); m++) {
+		  if(!os2.Contains(os1[m])) {
+		    os1.Delete(m);
+		    m--;
+		  }
+		}
+	      }
+	    if(!os1.Size()) continue;
+	    if(os1.Size()>1) {
+	      throw NgException("SurfaceElement identified with more than one other??");
+	    }
+	    const Element2d & sel2 = (*this)[sei];
+	    FlatArray<const PointIndex> points2 = sel2.PNums();
+	    has_ided_sels = true;
+	    ided_sel[sei] = os1[0];
+	    ided_sel[os1[0]] = sei;
+	  }
+      }
+    // build sel data to send
+    auto iterate_sels = [&](auto f) {
+      for (SurfaceElementIndex sei = 0; sei < GetNSE(); sei++ )
+	{
+	  const Element2d & sel = (*this)[sei];
+	  int dest = (*this)[sei].GetPartition();
+	  f(sei, sel, dest);
+	  if(ided_sel[sei]!=-1)
+	    {
+	      int dest2 = (*this)[ided_sel[sei]].GetPartition();
+	      f(sei, sel, dest2);
+	    }
+	}      
+    };
+    Array <int> nlocsel(ntasks), bufsize(ntasks);
     nlocsel = 0;
     bufsize = 1;
-
-    for (int sei = 1; sei <= GetNSE(); sei++ )
-      {
-	const Element2d & sel = SurfaceElement (sei);
-	int dest = sel.GetPartition();
-	nlocsel[dest] ++;
+    iterate_sels([&](SurfaceElementIndex sei, const Element2d & sel, int dest){
+	nlocsel[dest]++;
 	bufsize[dest] += 4 + 2*sel.GetNP();
-      }
-    
+      });
     TABLE<int> selbuf(bufsize);
-
     for (int dest = 1; dest < ntasks; dest++ )
       selbuf.Add (dest, nlocsel[dest]);
-
-    for (int sei = 1; sei <= GetNSE(); sei ++ )
-      {
-	const Element2d & sel = SurfaceElement (sei);
-	int dest = sel.GetPartition();
-
+    iterate_sels([&](SurfaceElementIndex sei, const auto & sel, int dest) {
 	selbuf.Add (dest, sei);
 	selbuf.Add (dest, sel.GetIndex());
 	// selbuf.Add (dest, 0);
 	selbuf.Add (dest, sel.GetNP());
-	
 	for ( int ii = 1; ii <= sel.GetNP(); ii++)
 	  {
 	    selbuf.Add (dest, sel.PNum(ii));
 	    selbuf.Add (dest, sel.GeomInfoPi(ii).trignum);
 	  }
-      }
-
+      });
+    // distribute sel data
     for (int dest = 1; dest < ntasks; dest++)
       sendrequests.Append (MyMPI_ISend(selbuf[dest], dest, MPI_TAG_MESH+4));
+    
 
-
+    /** Segments **/
     PrintMessage ( 3, "Sending Edge Segments");
-
-    
-    Array <int> nloc(ntasks); 
-    nloc = 0;
-    bufsize = 1;
-      
-    for (int i = 1; i <= GetNSeg(); i++ )
+    auto iterate_segs1 = [&](auto f) {
+      Array<SegmentIndex> osegs1, osegs2, osegs_both;
+      Array<int> type1, type2;
+      for(SegmentIndex segi = 0; segi < GetNSeg(); segi++)
+	{
+	  const Segment & seg = (*this)[segi];
+	  int segnp = seg.GetNP();
+	  PointIndex pi1 = seg[0];
+	  auto ided1 = per_verts[pi1];
+	  PointIndex pi2 = seg[1];
+	  auto ided2 = per_verts[pi2];
+	  if (!(ided1.Size() && ided2.Size())) continue;
+	  osegs1.SetSize(0);
+	  type1.SetSize(0);
+	  for (int l = 0; l<ided1.Size(); l++)
+	    {
+	      auto ospart = GetTopology().GetVertexSegments(ided1[l]);
+	      for(int j=0; j<ospart.Size(); j++)
+		{
+		  if(osegs1.Contains(ospart[j]))
+		    throw NgException("Periodic Mesh did something weird.");
+		  osegs1.Append(ospart[j]);
+		  type1.Append(idents.GetSymmetric(pi1, ided1[l]));
+		}
+	    }
+	  osegs2.SetSize(0);
+	  type2.SetSize(0);
+	  for (int l = 0; l<ided2.Size(); l++)
+	    {
+	      auto ospart = GetTopology().GetVertexSegments(ided2[l]);
+	      for(int j=0; j<ospart.Size(); j++)
+		{
+		  if(osegs2.Contains(ospart[j]))
+		    throw NgException("Periodic Mesh did something weird.");
+		  osegs2.Append(ospart[j]);
+		  type2.Append(idents.GetSymmetric(pi2, ided2[l]));
+		}
+	    }
+	  osegs_both.SetSize(0);
+	  for (int l = 0; l<osegs1.Size(); l++) {
+	    auto pos = osegs2.Pos(osegs1[l]);
+	    if (pos == -1) continue;
+	    if (type1[l] != type2[pos]) continue;
+	    osegs_both.Append(osegs1[l]);
+	  }
+	  for(int l = 0; l<osegs_both.Size(); l++) {
+	    int segnp = (*this)[osegs_both[l]].GetNP();
+	    if(segnp!=segnp)
+	      throw NgException("Tried to identify non-curved and curved Segment!");
+	  }
+	  for(int l = 0; l<osegs_both.Size(); l++) {
+	    f(segi, osegs_both[l]);
+	  }
+	}
+    };
+    Array<int> per_seg_size(GetNSeg());
+    per_seg_size = 0;
+    iterate_segs1([&](SegmentIndex segi1, SegmentIndex segi2)
+		  { per_seg_size[segi1]++; });
+    TABLE<SegmentIndex> per_seg(per_seg_size);
+    iterate_segs1([&](SegmentIndex segi1, SegmentIndex segi2)
+		  { per_seg.Add(segi1, segi2); });
+    // make per_seg transitive
+    auto iterate_per_seg_trans = [&](auto f){
+      Array<SegmentIndex> allsegs;
+      for (SegmentIndex segi = 0; segi < GetNSeg(); segi++)
+	{
+	  allsegs.SetSize(0);
+	  allsegs.Append(per_seg[segi]);
+	  bool changed = true;
+	  while (changed)
+	    {
+	      changed = false;
+	      for (int j = 0; j<allsegs.Size(); j++)
+		{
+		  auto persegs2 = per_seg[allsegs[j]];
+		  for (int l = 0; l<persegs2.Size(); l++)
+		    {
+		      auto addseg = persegs2[l];
+		      if (allsegs.Contains(addseg) || addseg==segi) continue;
+		      allsegs.Append(addseg);
+		      changed = true;
+		    }
+		}
+	    }
+	  f(segi, allsegs);
+	}
+    };
+    iterate_per_seg_trans([&](SegmentIndex segi, Array<SegmentIndex> & segs){
+	for (int j = 0; j < segs.Size(); j++)
+	  per_seg_size[segi] = segs.Size();
+      });
+    TABLE<SegmentIndex> per_seg_trans(per_seg_size);
+    iterate_per_seg_trans([&](SegmentIndex segi, Array<SegmentIndex> & segs){
+	for (int j = 0; j < segs.Size(); j++)
+	  per_seg_trans.Add(segi, segs[j]);
+      });
+    // build segment data
+    Array<int> dests;
+    auto iterate_segs2 = [&](auto f)
       {
-	const Segment & seg = LineSegment (i);
-	int dest = seg.GetPartition();
-	nloc[dest] ++;
-	bufsize[dest] += 14;
-      }
-    
+	for (SegmentIndex segi = 0; segi<GetNSeg(); segi++)
+	  {
+	    const Segment & seg = (*this)[segi];
+	    dests.SetSize(0);
+	    dests.Append(seg.GetPartition());
+	    for (int l = 0; l < per_seg_trans[segi].Size(); l++)
+	      {
+		int dest2 = (*this)[per_seg_trans[segi][l]].GetPartition();
+		if(!dests.Contains(dest2))
+		  dests.Append(dest2);
+	      }
+	    for (int l = 0; l < dests.Size(); l++)
+	      f(segi, seg, dests[l]);
+	  }
+      };
+    Array<int> nloc_seg(ntasks);
+    // bufsize = 1; //was originally this - why??
+    bufsize = 0;
+    nloc_seg = 0;
+    iterate_segs2([&](auto segi, const auto & seg, int dest)
+		  {
+		    nloc_seg[dest]++;
+		    bufsize[dest] += 14;
+		  });
     TABLE<double> segm_buf(bufsize);
-    
-    /*
-    for (int dest = 1; dest < ntasks; dest++ )
-      segm_buf.Add (dest, nloc[dest]);
-    */
-    for (int i = 1; i <= GetNSeg(); i++ )
-      {
-	const Segment & seg = LineSegment (i);
-	int dest = seg.GetPartition();
-	
-	segm_buf.Add (dest, i);
-	segm_buf.Add (dest, seg.si);
-	segm_buf.Add (dest, seg.pnums[0]);
-	segm_buf.Add (dest, seg.pnums[1]);
-	segm_buf.Add (dest, seg.geominfo[0].trignum);
-	segm_buf.Add (dest, seg.geominfo[1].trignum);
-	segm_buf.Add (dest, seg.surfnr1);
-	segm_buf.Add (dest, seg.surfnr2);
-	segm_buf.Add (dest, seg.edgenr);
-	segm_buf.Add (dest, seg.epgeominfo[0].dist);
-	segm_buf.Add (dest, seg.epgeominfo[1].edgenr);
-	segm_buf.Add (dest, seg.epgeominfo[1].dist);
-	segm_buf.Add (dest, seg.singedge_right);
-	segm_buf.Add (dest, seg.singedge_left);
-      }
-    
+    iterate_segs2([&](auto segi, const auto & seg, int dest)
+		  {
+		    segm_buf.Add (dest, segi);
+		    segm_buf.Add (dest, seg.si);
+		    segm_buf.Add (dest, seg.pnums[0]);
+		    segm_buf.Add (dest, seg.pnums[1]);
+		    segm_buf.Add (dest, seg.geominfo[0].trignum);
+		    segm_buf.Add (dest, seg.geominfo[1].trignum);
+		    segm_buf.Add (dest, seg.surfnr1);
+		    segm_buf.Add (dest, seg.surfnr2);
+		    segm_buf.Add (dest, seg.edgenr);
+		    segm_buf.Add (dest, seg.epgeominfo[0].dist);
+		    segm_buf.Add (dest, seg.epgeominfo[1].edgenr);
+		    segm_buf.Add (dest, seg.epgeominfo[1].dist);
+		    segm_buf.Add (dest, seg.singedge_right);
+		    segm_buf.Add (dest, seg.singedge_left);
+		  });
+    // distrubute segment data
     for (int dest = 1; dest < ntasks; dest++)
       sendrequests.Append (MyMPI_ISend(segm_buf[dest], dest, MPI_TAG_MESH+5));
 
-    /*
-    Array <int> nlocseg(ntasks), segi(ntasks);
-    for ( int i = 0; i < ntasks; i++)
-      {
-	nlocseg[i] = 0;
-	bufsize[i] = 0;
-	segi[i] = 0;
-      }
-
-    for (int segi = 1; segi <= GetNSeg(); segi ++ )
-      {
-	Array<int> volels;
-	const MeshTopology & topol = GetTopology();
-	topol . GetSegmentSurfaceElements ( segi, volels );
-        for (int j = 0; j < volels.Size(); j++)
-          {
-            int ei = volels[j];
-            if ( ei > 0 && ei <= GetNSE() )
-              {
-                const Element2d & el = SurfaceElement (ei);
-                int dest = el.GetPartition();
-		nlocseg[dest] ++;
-		bufsize[dest] += 14;
-              }
-	  }
-      }
-
-    TABLE<double> segmbuf(bufsize);
-
-    for ( int ls=1; ls <= GetNSeg(); ls++)
-      {
-	Array<int> volels;
-	GetTopology().GetSegmentSurfaceElements ( ls, volels );
-	const Segment & seg = LineSegment (ls);
-
-        for (int j = 0; j < volels.Size(); j++)
-          {
-            int ei = volels[j];
-            if ( ei > 0 && ei <= GetNSE() )
-              {
-                const Element2d & el = SurfaceElement (ei);
-                int dest = el.GetPartition();
-
-		if ( dest > 0 )
-		  {
-		    segmbuf.Add (dest, ls);
-		    segmbuf.Add (dest, seg.si);
-		    segmbuf.Add (dest, seg.pnums[0]);
-		    segmbuf.Add (dest, seg.pnums[1]);
-		    segmbuf.Add (dest, seg.geominfo[0].trignum);
-		    segmbuf.Add (dest, seg.geominfo[1].trignum);
-		    segmbuf.Add (dest, seg.surfnr1);
-		    segmbuf.Add (dest, seg.surfnr2);
-		    segmbuf.Add (dest, seg.edgenr);
-		    segmbuf.Add (dest, seg.epgeominfo[0].dist);
-		    segmbuf.Add (dest, seg.epgeominfo[1].edgenr);
-		    segmbuf.Add (dest, seg.epgeominfo[1].dist);
-		    segmbuf.Add (dest, seg.singedge_right);
-		    segmbuf.Add (dest, seg.singedge_left);
-		    segi[dest] += 14;
-		  }
-		// paralleltop -> SetDistantSegm ( dest, ls, int ( segi[dest] / 14 ) );
-	      }
-	  }
-      }
-
-    for ( int dest = 1; dest < ntasks; dest++)
-      sendrequests.Append (MyMPI_ISend(segmbuf[dest], dest, MPI_TAG_MESH+5));
-    */
-
     PrintMessage ( 3, "now wait ...");
 
     MPI_Waitall (sendrequests.Size(), &sendrequests[0], MPI_STATUS_IGNORE);
@@ -595,7 +750,16 @@ namespace netgen
     int timer_sels = NgProfiler::CreateTimer ("Receive surface elements");
     NgProfiler::RegionTimer reg(timer);
 
-
+    int dim;
+    MyMPI_Bcast(dim);
+    SetDimension(dim);
+    
+    // Receive number of local elements
+    int nelloc;
+    MPI_Scatter (NULL, 0, MPI_INT,
+		 &nelloc, 1, MPI_INT, 0, MPI_COMM_WORLD);
+    paralleltop -> SetNE (nelloc);
+    
     // string st;
 
     // receive vertices
@@ -604,6 +768,7 @@ namespace netgen
     Array<int> verts;
     MyMPI_Recv (verts, 0, MPI_TAG_MESH+1);
 
+
     int numvert = verts.Size();
     paralleltop -> SetNV (numvert);
     
@@ -623,6 +788,31 @@ namespace netgen
     MPI_Datatype mptype = MeshPoint::MyGetMPIType();
     MPI_Status status;
     MPI_Recv( &points[1], numvert, mptype, 0, MPI_TAG_MESH+1, MPI_COMM_WORLD, &status);
+
+    Array<int> pp_data;
+    MyMPI_Recv(pp_data, 0, MPI_TAG_MESH+1);
+
+
+    int maxidentnr = pp_data[0];
+    auto & idents = GetIdentifications();
+    for (int idnr = 1; idnr < maxidentnr+1; idnr++)
+      {
+	
+    	idents.SetType(idnr, (Identifications::ID_TYPE)pp_data[idnr]);
+      }
+
+    int offset = 2*maxidentnr+1;
+    for(int idnr = 1; idnr < maxidentnr+1; idnr++)
+      {
+    	int npairs = pp_data[maxidentnr+idnr];
+    	FlatArray<int> pairdata(2*npairs, &pp_data[offset]);
+    	offset += 2*npairs;
+	for (int k = 0; k<npairs; k++) {
+	  PointIndex loc1 = glob2loc_vert_ht.Get(pairdata[2*k]);
+	  PointIndex loc2 = glob2loc_vert_ht.Get(pairdata[2*k+1]);
+	  idents.Add(loc1, loc2, idnr);
+	}
+      }
     
     Array<int> dist_pnums;
     MyMPI_Recv (dist_pnums, 0, MPI_TAG_MESH+1);
@@ -694,7 +884,6 @@ namespace netgen
 	      tri.PNum(j) = glob2loc_vert_ht.Get (selbuf[ii++]);
 	      tri.GeomInfoPi(j).trignum = selbuf[ii++];
 	    }
-	  
 	  paralleltop->SetLoc2Glob_SurfEl ( sel+1, globsel );
 	  AddSurfaceElement (tri);
 	  sel ++;
@@ -903,51 +1092,87 @@ namespace netgen
       LineSegment(i+1).SetPartition(epart[i+GetNE()+GetNSE()] + 1);
 
 
+    // surface elements attached to volume elements
+    Array<bool, PointIndex::BASE> boundarypoints (GetNP());
+    boundarypoints = false;
+
+    if(GetDimension() == 3)
+      for (SurfaceElementIndex sei = 0; sei < GetNSE(); sei++)
+	{
+	  const Element2d & el = (*this)[sei];
+	  for (int j = 0; j < el.GetNP(); j++)
+	    boundarypoints[el[j]] = true;
+	}
+    else
+      for (SegmentIndex segi = 0; segi < GetNSeg(); segi++)
+	{
+	  const Segment & seg = (*this)[segi];
+	  for (int j = 0; j < 2; j++)
+	    boundarypoints[seg[j]] = true;
+	}
+
+    
+    // Build Pnt2Element table, boundary points only
+    Array<int, PointIndex::BASE> cnt(GetNP());
+    cnt = 0;
+
+    auto loop_els_2d = [&](auto f) {
+      for (SurfaceElementIndex sei = 0; sei < GetNSE(); sei++)
+	{
+	  const Element2d & el = (*this)[sei];
+	  cout << "surf-el " << sei << " verts: " << endl;
+	  for (int j = 0; j < el.GetNP(); j++) {
+	    cout << el[j] << " ";
+	    f(el[j], sei);
+	  }
+	  cout << endl;
+	}
+    };
+    auto loop_els_3d = [&](auto f) {
+      for (ElementIndex ei = 0; ei < GetNE(); ei++)
+	{
+	  const Element & el = (*this)[ei];
+	  for (int j = 0; j < el.GetNP(); j++)
+	    f(el[j], ei);
+	}
+    };
+    auto loop_els = [&](auto f)
+      {
+	if (GetDimension() == 3 ) 
+	  loop_els_3d(f);
+	else
+	  loop_els_2d(f);
+      };
+
+    
+    loop_els([&](auto vertex, int index)
+	{
+	  if(boundarypoints[vertex])
+	    cnt[vertex]++;
+	});
+    cout << "count: " << endl << cnt << endl;
+    TABLE<int, PointIndex::BASE> pnt2el(cnt);
+    loop_els([&](auto vertex, int index)
+	{
+	  if(boundarypoints[vertex])
+	    pnt2el.Add(vertex, index);
+	});
+
 
     if (GetDimension() == 3)
       {
-	
-	// surface elements attached to volume elements
-	Array<bool, PointIndex::BASE> boundarypoints (GetNP());
-	boundarypoints = false;
-	
-	for (SurfaceElementIndex sei = 0; sei < GetNSE(); sei++)
-	  {
-	    const Element2d & el = (*this)[sei];
-	    for (int j = 0; j < el.GetNP(); j++)
-	      boundarypoints[el[j]] = true;
-	  }
-	// Build Pnt2Element table, boundary points only
-	Array<int, PointIndex::BASE> cnt(GetNP());
-	cnt = 0;
-	for (ElementIndex ei = 0; ei < GetNE(); ei++)
-	  {
-	    const Element & el = (*this)[ei];
-	    for (int j = 0; j < el.GetNP(); j++)
-	      if (boundarypoints[el[j]])
-		cnt[el[j]]++;
-	  }
-	TABLE<ElementIndex, PointIndex::BASE> pnt2el(cnt);
-	cnt = 0;
-	for (ElementIndex ei = 0; ei < GetNE(); ei++)
-	  {
-	    const Element & el = (*this)[ei];
-	    for (int j = 0; j < el.GetNP(); j++)
-	      if (boundarypoints[el[j]])
-		pnt2el.Add (el[j], ei);
-	  }
-	
 	for (SurfaceElementIndex sei = 0; sei < GetNSE(); sei++)
 	  {
 	    Element2d & sel = (*this)[sei];
 	    PointIndex pi1 = sel[0];
-	    FlatArray<ElementIndex> els = pnt2el[pi1];
+	    // FlatArray<ElementIndex> els = pnt2el[pi1];
+	    FlatArray<int> els = pnt2el[pi1];
 	    
 	    sel.SetPartition (-1);
 	    
 	    for (int j = 0; j < els.Size(); j++)
 	      {
-		const Element & el = (*this)[els[j]];
+		const Element & el = (*this)[ElementIndex(els[j])];
 		
 		bool hasall = true;
 		
@@ -976,13 +1201,13 @@ namespace netgen
 	  {
 	    Segment & sel = (*this)[si];
 	    PointIndex pi1 = sel[0];
-	    FlatArray<ElementIndex> els = pnt2el[pi1];
+	    FlatArray<int> els = pnt2el[pi1];
 	    
 	    sel.SetPartition (-1);
 	    
 	    for (int j = 0; j < els.Size(); j++)
 	      {
-		const Element & el = (*this)[els[j]];
+		const Element & el = (*this)[ElementIndex(els[j])];
 		
 		bool haspi[9] = { false };  // max surfnp
 		
@@ -1004,7 +1229,36 @@ namespace netgen
 	    if (sel.GetPartition() == -1)
 	      cerr << "no volume element found" << endl;
 	  }
-	
+      }
+    else
+      {
+	for (SegmentIndex segi = 0; segi < GetNSeg(); segi++)
+	  {
+	    Segment & seg = (*this)[segi];
+	    seg.SetPartition(-1);
+	    PointIndex pi1 = seg[0];
+
+	    FlatArray<int> sels = pnt2el[pi1];
+	    for (int j = 0; j < sels.Size(); j++)
+	      {
+		SurfaceElementIndex sei = sels[j];
+		Element2d & se = (*this)[sei];
+		bool found = false;
+		for (int l = 0; l < se.GetNP(); l++ && !found)
+		  found |= (se[l]==seg[1]);
+		if(found) {
+		  seg.SetPartition(se.GetPartition());
+		  break;
+		}
+	      }
+	    
+	    if (seg.GetPartition() == -1) {
+	      cout << endl << "segi: " << segi << endl;
+	      cout << "points: " << seg[0] << " " << seg[1] << endl;
+	      cout << "surfels: " << endl << sels << endl;
+	      throw NgException("no surface element found");
+	    }
+	  }
 	
       }
   }