diff --git a/unidist/core/backends/mpi/core/communication.py b/unidist/core/backends/mpi/core/communication.py
index 8dfd6134..ed88e757 100755
--- a/unidist/core/backends/mpi/core/communication.py
+++ b/unidist/core/backends/mpi/core/communication.py
@@ -31,7 +31,6 @@
 
 # Logger configuration
 logger = common.get_logger("communication", "communication.log")
-logger1 = common.get_logger("communication1", "communication1.log")
 is_logger_header_printed = False
 
 
@@ -465,18 +464,20 @@ def mpi_send_buffer(comm, buffer, dest_rank, data_type=MPI.CHAR, buffer_size=Non
     if buffer_size:
         comm.send(buffer_size, dest=dest_rank, tag=common.MPITag.OBJECT)
     else:
-        buffer_size = len(buffer)        
-    PARTITION_SIZE = 100000
-    partitions=list(range(0, buffer_size,PARTITION_SIZE))
+        buffer_size = len(buffer)
+    block_size = pkl5._bigmpi.blocksize
+    partitions = list(range(0, buffer_size, block_size))
     partitions.append(buffer_size)
-    #with pkl5._bigmpi() as bigmpi:
-    if True:
-        for i,_ in enumerate(partitions):
-            if i+1<len(partitions):
-                logger1.debug(f" in send i={i} current={comm.rank}, destination={dest_rank}")
-                temp=buffer[partitions[i]:partitions[i+1]]
-                comm.Send([buffer[partitions[i]:partitions[i+1]],data_type], dest=dest_rank, tag=common.MPITag.BUFFER )
-                
+    with pkl5._bigmpi as bigmpi:
+        for i, _ in enumerate(partitions):
+            if i + 1 < len(partitions):
+                comm.Send(
+                    bigmpi(buffer[partitions[i] : partitions[i + 1]]),
+                    dest=dest_rank,
+                    tag=common.MPITag.BUFFER,
+                )
+
+
 def mpi_isend_buffer(comm, buffer_size, buffer, dest_rank):
     """
     Send buffer object to another MPI rank in a non-blocking way.
@@ -505,18 +506,19 @@ def mpi_isend_buffer(comm, buffer_size, buffer, dest_rank):
     requests = []
     h1 = comm.isend(buffer_size, dest=dest_rank, tag=common.MPITag.OBJECT)
     requests.append((h1, None))
-    
-    PARTITION_SIZE = 100000
-    partitions=list(range(0, buffer_size,PARTITION_SIZE))
+    block_size = pkl5._bigmpi.blocksize
+    partitions = list(range(0, buffer_size, block_size))
     partitions.append(buffer_size)
-    #with pkl5._bigmpi() as bigmpi:
-    if True:
-        for i,_ in enumerate(partitions):
-            if i+1<len(partitions):
-                temp=buffer[partitions[i]:partitions[i+1]]
-                h2=comm.Isend([buffer[partitions[i]:partitions[i+1]],MPI.CHAR], dest=dest_rank, tag=common.MPITag.BUFFER )
+    with pkl5._bigmpi as bigmpi:
+        for i, _ in enumerate(partitions):
+            if i + 1 < len(partitions):
+                h2 = comm.Isend(
+                    bigmpi(buffer[partitions[i] : partitions[i + 1]]),
+                    dest=dest_rank,
+                    tag=common.MPITag.BUFFER,
+                )
                 requests.append((h2, buffer))
-            
+
     return requests
 
 
@@ -548,19 +550,16 @@ def mpi_recv_buffer(comm, source_rank, result_buffer=None):
         result_buffer = bytearray(buf_size)
     else:
         buf_size = len(result_buffer)
-    PARTITION_SIZE = 100000
-    partitions=list(range(0, buf_size,PARTITION_SIZE))
+    block_size = pkl5._bigmpi.blocksize
+    partitions = list(range(0, buf_size, block_size))
     partitions.append(buf_size)
-    #with pkl5._bigmpi as bigmpi:
-    if True:
-        logger1.debug(f" in recv {list(partitions)}")
-        for i,_ in enumerate(partitions):
-            if i+1<len(partitions):
-                logger1.debug(f" in recv {i}")
-                temp=bytearray(partitions[i+1]-partitions[i])
-                comm.Recv(temp,  source=source_rank, tag=common.MPITag.BUFFER )
-                result_buffer[partitions[i]:partitions[i+1]]=temp
-    
+    with pkl5._bigmpi as bigmpi:
+        for i, _ in enumerate(partitions):
+            if i + 1 < len(partitions):
+                temp = bytearray(partitions[i + 1] - partitions[i])
+                comm.Recv(bigmpi(temp), source=source_rank, tag=common.MPITag.BUFFER)
+                result_buffer[partitions[i] : partitions[i + 1]] = temp
+
     return result_buffer