diff --git a/src/connection_pool.c b/src/connection_pool.c
index 7c6cbae..ad0207e 100644
--- a/src/connection_pool.c
+++ b/src/connection_pool.c
@@ -24,9 +24,9 @@
 #include "connection_pool.h"
 
 ConnectionCallbacks g_connection_callbacks[2] = {
-    {NULL, NULL, conn_pool_connect_server_ex1,
+    {NULL, NULL, NULL, conn_pool_connect_server_ex1,
         conn_pool_disconnect_server, NULL},
-    {NULL, NULL, NULL, NULL, NULL}
+    {NULL, NULL, NULL, NULL, NULL, NULL}
 };
 
 static int node_init_for_socket(ConnectionNode *node,
@@ -41,8 +41,8 @@ static int node_init_for_rdma(ConnectionNode *node,
 {
     node->conn = (ConnectionInfo *)(node + 1);
     node->conn->arg1 = node->conn->args + cp->extra_data_size;
-    return g_connection_callbacks[fc_comm_type_rdma].init_connection(
-            node->conn, cp->extra_params.buffer_size, cp->extra_params.pd);
+    return G_RDMA_CONNECTION_CALLBACKS.init_connection(node->conn,
+            cp->extra_params.buffer_size, cp->extra_params.pd);
 }
 
 int conn_pool_init_ex1(ConnectionPool *cp, int connect_timeout,
@@ -81,8 +81,8 @@ int conn_pool_init_ex1(ConnectionPool *cp, int connect_timeout,
     }
 
     if (extra_params != NULL) {
-        extra_connection_size = g_connection_callbacks
-            [fc_comm_type_rdma].get_connection_size();
+        extra_connection_size = G_RDMA_CONNECTION_CALLBACKS.
+            get_connection_size();
         obj_init_func = (fast_mblock_object_init_func)node_init_for_rdma;
         cp->extra_params = *extra_params;
     } else {
@@ -595,6 +595,7 @@ int conn_pool_global_init_for_rdma()
     }
 
     callbacks = g_connection_callbacks + fc_comm_type_rdma;
+    LOAD_API(callbacks, alloc_pd);
     LOAD_API(callbacks, get_connection_size);
     LOAD_API(callbacks, init_connection);
     LOAD_API(callbacks, make_connection);
diff --git a/src/connection_pool.h b/src/connection_pool.h
index daf794a..69f6a6f 100644
--- a/src/connection_pool.h
+++ b/src/connection_pool.h
@@ -57,6 +57,9 @@ typedef struct {
     char args[0];   //for extra data
 } ConnectionInfo;
 
+struct ibv_pd;
+typedef struct ibv_pd *(*fc_alloc_pd_callback)(const char **ip_addrs,
+        const int count, const int port);
 typedef int (*fc_get_connection_size_callback)();
 typedef int (*fc_init_connection_callback)(ConnectionInfo *conn,
         const int buffer_size, void *arg);
@@ -67,6 +70,7 @@ typedef void (*fc_close_connection_callback)(ConnectionInfo *conn);
 typedef void (*fc_destroy_connection_callback)(ConnectionInfo *conn);
 
 typedef struct {
+    fc_alloc_pd_callback alloc_pd;
     fc_get_connection_size_callback get_connection_size;
     fc_init_connection_callback init_connection;
     fc_make_connection_callback make_connection;
@@ -74,7 +78,6 @@ typedef struct {
     fc_destroy_connection_callback destroy_connection;
 } ConnectionCallbacks;
 
-struct ibv_pd;
 typedef struct {
     int buffer_size;
     struct ibv_pd *pd;
@@ -132,6 +135,8 @@ extern ConnectionCallbacks g_connection_callbacks[2];
 
 int conn_pool_global_init_for_rdma();
 
+#define G_RDMA_CONNECTION_CALLBACKS g_connection_callbacks[fc_comm_type_rdma]
+
 /**
 *   init ex function
 *   parameters:
@@ -394,6 +399,8 @@ static inline const char *fc_comm_type_str(const FCCommunicationType type)
             return "socket";
         case fc_comm_type_rdma:
             return "rdma";
+        case fc_comm_type_both:
+            return "both";
         default:
             return "unkown";
     }
diff --git a/src/server_id_func.c b/src/server_id_func.c
index 19790d7..0c25028 100644
--- a/src/server_id_func.c
+++ b/src/server_id_func.c
@@ -342,11 +342,13 @@ static int fc_server_load_one_group(FCServerConfig *ctx,
 {
     int result;
     FCServerGroupInfo *group;
+    IniFullContext full_ini_ctx;
     char new_name[FAST_INI_ITEM_NAME_SIZE];
     char *port_str;
     char *net_type;
     char *ip_prefix;
     char *comm_type;
+    int buffer_size;
 
     strcpy(new_name, section_name);
     group = ctx->group_array.groups + ctx->group_array.count;
@@ -404,6 +406,17 @@ static int fc_server_load_one_group(FCServerConfig *ctx,
         return result;
     }
 
+    if (group->comm_type == fc_comm_type_sock) {
+        group->buffer_size = 0;
+    } else {
+        FAST_INI_SET_FULL_CTX_EX(full_ini_ctx, config_filename,
+                section_name, ini_context);
+        buffer_size = iniGetByteValue(section_name, "buffer_size",
+                ini_context, 256 * 1024);
+        group->buffer_size = iniCheckAndCorrectIntValue(&full_ini_ctx,
+                "buffer_size", buffer_size, 8 * 1024, 8 * 1024 * 1024);
+    }
+
     ctx->group_array.count++;
     return 0;
 }
@@ -1382,13 +1395,22 @@ static int fc_groups_to_string(FCServerConfig *ctx, FastBuffer *buffer)
 
         fast_buffer_append(buffer,
                 "[%s%.*s]\n"
-                "port = %d\n"
-                "communication = %s\n"
-                "net_type = %s\n"
-                "ip_prefix = %.*s\n\n",
+                "port = %d\n",
                 GROUP_SECTION_PREFIX_STR,
                 group->group_name.len, group->group_name.str,
-                group->port, fc_comm_type_str(group->comm_type),
+                group->port);
+
+        if (group->comm_type != fc_comm_type_sock) {
+            fast_buffer_append(buffer,
+                    "communication = %s\n"
+                    "buffer_size = %d\n",
+                    fc_comm_type_str(group->comm_type),
+                    group->buffer_size);
+        }
+
+        fast_buffer_append(buffer,
+                "net_type = %s\n"
+                "ip_prefix = %.*s\n\n",
                 net_type_caption, group->filter.ip_prefix.len,
                 group->filter.ip_prefix.str);
     }
@@ -1478,14 +1500,24 @@ static void fc_server_log_groups(FCServerConfig *ctx)
 {
     FCServerGroupInfo *group;
     FCServerGroupInfo *end;
+    char buff[1024];
+    char *p;
 
     end = ctx->group_array.groups + ctx->group_array.count;
     for (group=ctx->group_array.groups; group<end; group++) {
-        logInfo("group_name: %.*s, port: %d, communication: %s, net_type: %s, "
-                "ip_prefix: %.*s", group->group_name.len, group->group_name.str,
-                group->port, fc_comm_type_str(group->comm_type),
+        p = buff + sprintf(buff, "group_name: %.*s, port: %d",
+                group->group_name.len, group->group_name.str,
+                group->port);
+        if (group->comm_type != fc_comm_type_sock) {
+            p += sprintf(p, ", communication: %s, buffer_size: %d KB",
+                    fc_comm_type_str(group->comm_type),
+                    group->buffer_size / 1024);
+        }
+        p += sprintf(p, ", net_type: %s, ip_prefix: %.*s",
                 get_net_type_caption(group->filter.net_type),
                 group->filter.ip_prefix.len, group->filter.ip_prefix.str);
+
+        log_it1(LOG_INFO, buff, p - buff);
     }
 }
 
@@ -1668,3 +1700,34 @@ const FCAddressInfo *fc_server_get_address_by_peer(
 
     return *(addr_array->addrs);
 }
+
+struct ibv_pd *fc_alloc_rdma_pd(fc_alloc_pd_callback alloc_pd,
+        FCAddressPtrArray *address_array, int *result)
+{
+    char *ip_addrs[FC_MAX_SERVER_IP_COUNT];
+    char **ip_addr;
+    FCAddressInfo **addr;
+    FCAddressInfo **end;
+    struct ibv_pd *pd;
+    int port;
+
+    if (address_array->count == 0) {
+        port = 0;
+    } else {
+        port = address_array->addrs[0]->conn.port;
+    }
+
+    end = address_array->addrs + address_array->count;
+    for (addr=address_array->addrs, ip_addr=ip_addrs; addr<end; addr++) {
+        *ip_addr = (*addr)->conn.ip_addr;
+    }
+
+    if ((pd=alloc_pd((const char **)ip_addrs, address_array->
+                    count, port)) != NULL)
+    {
+        *result = 0;
+    } else {
+        *result = ENODEV;
+    }
+    return pd;
+}
diff --git a/src/server_id_func.h b/src/server_id_func.h
index 2355e90..c034936 100644
--- a/src/server_id_func.h
+++ b/src/server_id_func.h
@@ -58,6 +58,7 @@ typedef struct
     int port;          //default port
     int server_port;   //port in server section
     FCCommunicationType comm_type;
+    int buffer_size;  //for RDMA
     struct {
         int net_type;
         string_t ip_prefix;
@@ -246,6 +247,9 @@ int fc_server_make_connection_ex(FCAddressPtrArray *addr_array,
     fc_server_make_connection_ex(addr_array, conn, \
             service_name, connect_timeout, NULL, true)
 
+struct ibv_pd *fc_alloc_rdma_pd(fc_alloc_pd_callback alloc_pd,
+        FCAddressPtrArray *address_array, int *result);
+
 #ifdef __cplusplus
 }
 #endif