diff --git a/docs/Arguments.md b/docs/Arguments.md
index dfe06df9..d6c8b7fe 100644
--- a/docs/Arguments.md
+++ b/docs/Arguments.md
@@ -147,13 +147,13 @@ usage: -m llumnix.entrypoints.vllm.api_server [-h]
 
 `--migration-backend`
 - Communication backend of migration.
-- Possible choices: gloo, rayrpc, grpc, kvtransfer. [gloo, rayrpc] are available for vllm and [grpc, kvtransfer] are available for bladellm.
-- Default: "rayrpc"
+- Possible choices: gloo, rayrpc, nccl, grpc, kvtransfer. [gloo, rayrpc, nccl] are available for vllm and [grpc, kvtransfer] are available for bladellm.
+- Default: "gloo"
 
 `--migration-backend-transfer-type`
-- Transfer type for migration backend grpc and kvTransfer.
-- Possible choices: cuda_ipc, rdma, ""
-- Default: ""
+- Transfer type for migration backend kvTransfer.
+- Possible choices: cuda_ipc, rdma
+- Default: "rdma"
 
 `--migration-backend-server-address`
 - Address of grpc server for migration backend
@@ -161,7 +161,7 @@ usage: -m llumnix.entrypoints.vllm.api_server [-h]
 
 `--migration-backend-kvtransfer-naming-url`
 - URL of naming server for kvtransfer migration backend
-- Default: ""
+- Default: "file:/tmp/llumnix/naming/"
 
 `--migration-buffer-blocks`
 - Number of buffer blocks in migration.
diff --git a/llumnix/arg_utils.py b/llumnix/arg_utils.py
index 4bad0cd4..2386fa4f 100644
--- a/llumnix/arg_utils.py
+++ b/llumnix/arg_utils.py
@@ -318,7 +318,7 @@ def add_cli_args(parser: argparse.ArgumentParser) -> argparse.ArgumentParser:
         parser.add_argument('--migration-backend',
                             type=str,
                             choices=['gloo','nccl','rayrpc','grpc','kvtransfer'],
-                            help='communication backend of migration, [gloo, rayrpc] are available for vllm \
+                            help='communication backend of migration, [gloo, rayrpc, nccl] are available for vllm \
                                 and [grpc, kvtransfer] are available for bladellm')
         parser.add_argument('--migration-backend-transfer-type',
                             type=str,
diff --git a/llumnix/config/default.py b/llumnix/config/default.py
index 729cf76d..aa76ba30 100644
--- a/llumnix/config/default.py
+++ b/llumnix/config/default.py
@@ -105,12 +105,12 @@
 
 # Communication backend of migration
 _C.MANAGER.MIGRATION_BACKEND = "gloo"
-# Transfer type for migration backend grpc and kvTransfer
-_C.MANAGER.MIGRATION_BACKEND_TRANSFER_TYPE = ""
+# Transfer type for migration backend kvTransfer
+_C.MANAGER.MIGRATION_BACKEND_TRANSFER_TYPE = "rdma"
 # Address of grpc server for migration backend
 _C.MANAGER.MIGRATION_BACKEND_SERVER_ADDRESS = "127.0.0.1:50051"
 # URL of naming server for kvtransfer migration backend
-_C.MANAGER.MIGRATION_BACKEND_KVTRANSFER_NAMING_URL = ""
+_C.MANAGER.MIGRATION_BACKEND_KVTRANSFER_NAMING_URL = "file:/tmp/llumnix/naming/"
 # Timeout(s) for initializing migration backend
 _C.MANAGER.MIGRATION_BACKEND_INIT_TIMEOUT = 10.0
 # Number of cache blocks in migration