Orchestrating VNFs and VNFFG using Network Services Descriptor (NSD)

To enable dynamic composition of network services, NFV introduces Network Service Descriptors (NSDs) that specify the network service to be created. In Network Function Virtualization (NFV), Network Service (NS) is a set of network functions, that includes virtual network functions (VNFs), physical network functions (PNFs), and VNF forwarding graph (VNFFG) that defines connection between NFs 1, 2.

                 TOSCA                                        NFV
+------------------------------------------+         +--------------------+
|                                          |         |                    |
|           Service Template  <------------------------+ Network Service  |
|                                          |         |   Descriptor (NSD) |
| +-------------------+                    |         |                    |
| | Topology template |   +-------------+  |         |     +----------+   |
| |  +---------+      |   | Node types  <------------------+   VNFD   |   |
| |  |  Node   <----------+substitutable|  |         |     +----------+   |
| |  | Template|      |   +-------------+  |         |                    |
| |  +---------+      |                    |         |     +----------+   |
| |  +---------+      |   +-------------+  |      +--------+   VLD    |   |
| |  |  Node   <----------+ Node types  <---------+  |     +----------+   |
| |  | Template|      |   +-------------+  |         |                    |
| |  +---------+      |                    |         |     +----------+   |
| |  +---------+      |   +-------------+  |      +--------+  VNFFGD  |   |
| |  |  Node   <----------+ Group types <---------+  |     +----------+   |
| |  | Template|      |   +-------------+  |         |                    |
| |  +---------+      |                    |         |     +----------+   |
| |  +---------+      |                    |      +--------+   PNFD   |   |
| |  |  Node   |      |   +-------------+  |      |  |     +----------+   |
| |  | Template<----------+ Node types  <---------+  |                    |
| |  +---------+      |   +-------------+  |         +--------------------+
| |                   |                    |
| +-------------------+                    |
|                                          |
+------------------------------------------+

NSD in Ocata can be used for creating multiple (related) VNFs in one shot using a single TOSCA template.

In Rocky version, Tacker add VNFFG support in NSD. That lets users can use NSD to create VNFs and VNFFGs.

Note

For current implementation, Tacker does not support creating VLs/neutron networks using NSD (to support inter-VNF private VL).

This usage guide describes lifecycle of Network service descriptors and services.

Network Service creation procedure

Tacker uses Mistral to call actions to create Network Service. Firstly, Tacker extracts VNFDs from NSD template to create VNFs. When creating VNF tasks is on-success state (VNFs are in RUNNING state), nested VNFFGD template in NSD template is extracted and create_vnffg task is called to create VNFFGs.

When NSD does not have nested VNFFG template, Tacker does not invoke creating VNFFGs, only VNFs are created. Users can find detail implementation in 3

             +------------------------+
             |                        |
             |      NSD template      |
             |                        |
             |                        |
             +------------------------+
                         | extract templates
     +-------------------v---------------+
     |                                   |
+----v------------+            +---------v------+
|                 |            |                |
| VNFFGD templates|            |      VNFDs     |
|                 |            |                |
+----+------------+            +---------+------+
     |                                   |    create VNFs
     |                +-----------+------+-----------------+
     |                |           |                        |
     |                |           |                        |
     |           +----v---+   +---v----+              +----v---+
     |           |  VNF1  |   |  VNF2  |              |  VNFn  |
     |           +----+---+   +---+----+              +----+---+
     |                |           |                        |
     |                | +---------+                        |
     |                | | +--------------------------------+
     |                | | |
     |                | | |on-success
     |                | | |
     |            +---v-v-v---------+
     |            |      VNFFGs     |
     +------------>    (optional)   |
    create VNFFGs |                 |
                  +-----------------+

Network Service examples

With NS, Tacker can use NSD template to create VNFs and VNFFGs to make a chain between VNFs. In this document, we provide two NS examples:

  1. Deploy VNFs

In this scenario, users can use NSD template to create VNFs. There are no VNFFGs created. Templates are located in tacker/samples/tosca-templates/nsd.

  1. Deploy VNFs and VNFFG between 2 HTTP servers

In the second scenario, users can use NSD template to create 2 VNFs and 2 VNFFGs. Templates are located in tacker/samples/tosca-templates/vnffg-nsd.

The below diagram describes the second scenario, NSD is used to create VNF1, VNF2, VNFFG1 and VNFFG2. VNFFG1 will chain traffic from http_client to http_server go through VNF1 and VNF2, while VNFFG2 only route traffic go through VNF1.

                       +------------+        +------------+
                       |    VNF1    |        |    VNF2    |
                       |            |        |            |
                       |    CP12    |        |    CP22    |
                       +--^-+---^-+-+        +----^--+----+
                          | |   | |               |  |
                          | |   | |               |  |
+-------------+ VNFFG1    | |   | |               |  |               +-------------+
|             +-----------+ +---------------------+  +--------------->             |
| http_client |                 | |                                  | http_server |
|             +-----------------+ +---------------------------------->             |
+-------------+ VNFFG2                                               +-------------+

Note

VNF1 and VNF2 are just a name, that can be changed.

Users can look at document about VNF 4 and VNFFG 5 6 usage guide to know more detail about this scenarios.

Setup experiment environment

To support users easily create testing environment, Tacker provides some bash scripts to create http_client, http_server servers and default VIM0. Tacker also update information in ns_param.yaml file.

Users can go to contrib/tacker-config/, then run ns-config.sh script:

$ cd ~/tacker/contrib/tacker-config
$ ./ns-config.sh

After ns-config.sh is deployed, if there are no error, 2 new servers and a new default VIM will be launched and ns_param.yaml will be updated.

$ openstack server list
$ openstack vim list
$ cat ../../samples/tosca-templates/nsd/ns_param.yaml
$ cat ../../samples/tosca-templates/vnffg-nsd/ns_param.yaml

1. Using NSD to create VNFs

Once OpenStack along with Tacker has been successfully installed, deploying sample VNFD templates using sample-tosca-vnfd1.yaml 7 and sample-tosca-vnfd2.yaml 8.

$ cd ~/tacker/samples/tosca-templates/nsd
$ openstack vnf descriptor create --vnfd-file sample-tosca-vnfd1.yaml sample-tosca-vnfd1
$ openstack vnf descriptor create --vnfd-file sample-tosca-vnfd2.yaml sample-tosca-vnfd2

The following code represents sample NSD which instantiates the above VNFs.

Note

VNF descriptor names must be same as values in imports part in NSD template.

tosca_definitions_version: tosca_simple_profile_for_nfv_1_0_0

description: Import VNFDs(already on-boarded) with input parameters
imports:
    - sample-tosca-vnfd1
    - sample-tosca-vnfd2

topology_template:
  inputs:
    vl1_name:
      type: string
      description: name of VL1 virtuallink
      default: net_mgmt
    vl2_name:
      type: string
      description: name of VL2 virtuallink
      default: net0
  node_templates:
      VNF1:
        type: tosca.nodes.nfv.VNF1
        requirements:
          - virtualLink1: VL1
          - virtualLink2: VL2

      VNF2:
        type: tosca.nodes.nfv.VNF2

      VL1:
        type: tosca.nodes.nfv.VL
        properties:
          network_name: {get_input: vl1_name}
          vendor: tacker

      VL2:
        type: tosca.nodes.nfv.VL
        properties:
          network_name: {get_input: vl2_name}
          vendor: tacker

In above NSD template VL1 and VL2 are substituting the virtual links of VNF1.

To create Network Service, users can use two ways:

  1. Onboard the above NSD, then create NS from NSD.

$ openstack ns descriptor create --nsd-file sample-tosca-nsd.yaml NSD-template
$ openstack ns create --nsd-name NSD-template --param-file ns_param.yaml NS1
  1. Create NS directly from NSD

$ openstack ns create --nsd-template sample-tosca-nsd.yaml --param-file ns_param.yaml NS1

2. Using NSD to create VNFs and VNFFG

In this scenario, in the same way with above scenario, firstly, users need to create vnf descriptors, which is defined in NSD template.

$ cd ~/tacker/samples/tosca-templates/vnffg-nsd
$ openstack vnf descriptor create --vnfd-file tosca-vnfd1-sample.yaml sample-vnfd1
$ openstack vnf descriptor create --vnfd-file tosca-vnfd2-sample.yaml sample-vnfd2

The following code represents sample NSD which instantiates the above VNFs and VNFFG.

tosca_definitions_version: tosca_simple_profile_for_nfv_1_0_0

description: Import VNFDs(already on-boarded) with input parameters
imports:
    - sample-vnfd1
    - sample-vnfd2

topology_template:
  inputs:
    vl1_name:
      type: string
      description: name of VL1 virtuallink
      default: net_mgmt
    vl2_name:
      type: string
      description: name of VL2 virtuallink
      default: net0
    net_src_port_id:
      type: string
      description: neutron port id of source port
    ip_dest_prefix:
      type: string
      description: IP prefix of destination port

  node_templates:
    VNF1:
      type: tosca.nodes.nfv.VNF1
      requirements:
        - virtualLink1: VL1

    VNF2:
      type: tosca.nodes.nfv.VNF2

    VL1:
      type: tosca.nodes.nfv.VL
      properties:
        network_name: {get_input: vl1_name}
        vendor: tacker

    VL2:
      type: tosca.nodes.nfv.VL
      properties:
        network_name: {get_input: vl2_name}
        vendor: tacker

    Forwarding_path1:
      type: tosca.nodes.nfv.FP.TackerV2
      description: creates path inside ns (src_port->CP12->CP22->dst_port)
      properties:
        id: 51
        symmetrical: true
        policy:
          type: ACL
          criteria:
            - name: block_tcp
              classifier:
                network_src_port_id: {get_input: net_src_port_id}
                destination_port_range: 80-1024
                ip_proto: 6
                ip_dst_prefix: {get_input: ip_dest_prefix}
        path:
          - forwarder: sample-vnfd1
            capability: CP12
          - forwarder: sample-vnfd2
            capability: CP22

    Forwarding_path2:
      type: tosca.nodes.nfv.FP.TackerV2
      description: creates path inside ns (src_port->CP12->CP22->dst_port)
      properties:
        id: 52
        symmetrical: false
        policy:
          type: ACL
          criteria:
            - name: block_tcp
              classifier:
                network_src_port_id: {get_input: net_src_port_id}
                destination_port_range: 8080-8080
                ip_proto: 6
                ip_dst_prefix: {get_input: ip_dest_prefix}
        path:
          - forwarder: sample-vnfd1
            capability: CP12

  groups:

    VNFFG1:
      type: tosca.groups.nfv.VNFFG
      description: HTTP to Corporate Net
      properties:
        vendor: tacker
        version: 1.0
        number_of_endpoints: 2
        dependent_virtual_link: [VL1, VL2]
        connection_point: [CP12, CP22]
        constituent_vnfs: [sample-vnfd1, sample-vnfd2]
      members: [Forwarding_path1]

    VNFFG2:
      type: tosca.groups.nfv.VNFFG
      description: HTTP to Corporate Net
      properties:
        vendor: tacker
        version: 1.0
        number_of_endpoints: 1
        dependent_virtual_link: [VL1]
        connection_point: [CP12]
        constituent_vnfs: [sample-vnfd1]
      members: [Forwarding_path2]

To create Network Service, users can use two ways:

  1. Onboard the above NSD, then create NS from NSD.

$ openstack ns descriptor create --nsd-file tosca-multiple-vnffg-nsd.yaml NSD-VNFFG-template
$ openstack ns create --nsd-name NSD-VNFFG-template --param-file ns_param.yaml NS2
  1. Create NS directly from NSD

$ openstack ns create --nsd-template tosca-multiple-vnffg-nsd.yaml --param-file ns_param.yaml NS2

Result

The following commands shows the result of launching NS in second scenario. If users run the first scenario, some information about VNFFG is not listed, such as VNFFG ID and can not see any VNFFG is created.

$ openstack ns list --fit-width
+------------------+------+------------------+------------------+------------------+--------------------+----------------+
| ID               | Name | NSD ID           | VNF IDs          | VNFFG IDs        | Mgmt Urls          | Status         |
+------------------+------+------------------+------------------+------------------+--------------------+----------------+
| 23380f92-3e0a-45 | NS2  | 7ff1c49a-4e89-4b | {'VNF2': 'f92aad | {'VNFFG2':       | {'VNF2': {'VDU1':  | ACTIVE         |
| 39-877c-         |      | 66-9413-810715b8 | a2-c194-4906-b58 | '24f03f01-7a6d-  | '192.168.120.12'}, |                |
| b421dc8960b6     |      | 470e             | 5-e6c8201f0010', | 44ba-b8b8-086ab7 | 'VNF1': {'VDU1':   |                |
|                  |      |                  | 'VNF1':          | bd2f21',         | '192.168.120.3'}}  |                |
|                  |      |                  | '25686357-ebdf-  | 'VNFFG1': '3ccad |                    |                |
|                  |      |                  | 4b8e-ab04-7b34a5 | c6e-5702-4516    |                    |                |
|                  |      |                  | 66e21f'}         | -babd-           |                    |                |
|                  |      |                  |                  | 1013e9afffbf'}   |                    |                |
+------------------+------+------------------+------------------+------------------+--------------------+----------------+

$ openstack vnf graph list --fit-width
+------------------------------------+------------------------------------+-------------------------------------+--------+
| ID                                 | Name                               | VNFFGD ID                           | Status |
+------------------------------------+------------------------------------+-------------------------------------+--------+
| 24f03f01-7a6d-44ba-                | NS2_VNFFG2_a7f77e11-d847-4090-aa79 | 1f2bdd92-c313-4f1d-a423-51e66bc6f1d | ACTIVE |
| b8b8-086ab7bd2f21                  | -496610c522bf                      | 1                                   |        |
| 3ccadc6e-5702-4516-babd-           | NS2_VNFFG1_a7f77e11-d847-4090-aa79 | 9923e4ab-19d4-4ff5-b07b-            | ACTIVE |
| 1013e9afffbf                       | -496610c522bf                      | 0e82a61e2268                        |        |
+------------------------------------+------------------------------------+-------------------------------------+--------+

$ openstack vnf list --fit-width
+---------------------+---------------------+---------------------+--------+---------------------+-----------------------+
| ID                  | Name                | Mgmt Url            | Status | VIM ID              | VNFD ID               |
+---------------------+---------------------+---------------------+--------+---------------------+-----------------------+
| 25686357-ebdf-4b8e- | NS2_VNF_183c3dba-70 | {"VDU1":            | ACTIVE | 3ec1a3f0-058a-40e7- | 183c3dba-7090-4984-bb |
| ab04-7b34a566e21f   | 90-4984-bb57-e0dd11 | "192.168.120.3"}    |        | 83d2-cc8dd24af0ca   | 57-e0dd11045563       |
|                     | 045563_a7f77e11-d84 |                     |        |                     |                       |
|                     | 7-4090-aa79-496610c |                     |        |                     |                       |
|                     | 522bf               |                     |        |                     |                       |
| f92aada2-c194-4906- | NS2_VNF_3762c695-08 | {"VDU1":            | ACTIVE | 3ec1a3f0-058a-40e7- | 3762c695-08f1-4247    |
| b585-e6c8201f0010   | f1-4247-bfda-56d2f5 | "192.168.120.12"}   |        | 83d2-cc8dd24af0ca   | -bfda-56d2f565e8b7    |
|                     | 65e8b7_a7f77e11-d84 |                     |        |                     |                       |
|                     | 7-4090-aa79-496610c |                     |        |                     |                       |
|                     | 522bf               |                     |        |                     |                       |
+---------------------+---------------------+---------------------+--------+---------------------+-----------------------+

$ openstack vnf network forwarding path list
+--------------------------------------+------------------+--------+--------------------------------------+---------+
| ID                                   | Name             | Status | VNFFG ID                             | Path ID |
+--------------------------------------+------------------+--------+--------------------------------------+---------+
| 3d24b870-fe0d-4af9-a03f-9e0811859256 | Forwarding_path2 | ACTIVE | a601e938-a37b-493c-a48c-2c90aba73a77 | 52      |
| a2ca3a24-f02e-4629-b12c-54256886c050 | Forwarding_path1 | ACTIVE | 1f48603b-6740-4b94-a981-15de8c5c0fb3 | 51      |
+--------------------------------------+------------------+--------+--------------------------------------+---------+

$ openstack sfc port chain list --fit-width
+---------------------+---------------------+---------------------+---------------------+---------------------+----------+
| ID                  | Name                | Port Pair Groups    | Flow Classifiers    | Chain Parameters    | Chain ID |
+---------------------+---------------------+---------------------+---------------------+---------------------+----------+
| 2950fa88-d98f-4812  | NS2_VNFFG2_a7f77e11 | [u'e92feb43-4906-45 | [u'3eff5973-c612-43 | {u'symmetric':      |       51 |
| -830a-ae15452a8c08  | -d847-4090-aa79     | 21-852f-            | 83-aee2-d1eb05c832e | False,              |          |
|                     | -496610c522bf-port- | 1940c2f344a6']      | e']                 | u'correlation':     |          |
|                     | chain               |                     |                     | u'mpls'}            |          |
| 61c938f9-15a1-4ec8  | NS2_VNFFG1_a7f77e11 | [u'e92feb43-4906-45 | [u'b4cb5575-cb3c-41 | {u'symmetric':      |       52 |
| -8dec-44e5f8af70ff  | -d847-4090-aa79     | 21-852f-            | a3-8649-c69e0cd48db | False,              |          |
|                     | -496610c522bf-port- | 1940c2f344a6', u'82 | e']                 | u'correlation':     |          |
|                     | chain               | dab526-540e-4047    |                     | u'mpls'}            |          |
|                     |                     | -ba8a-              |                     |                     |          |
|                     |                     | c97c4cdbaef1']      |                     |                     |          |
+---------------------+---------------------+---------------------+---------------------+---------------------+----------+

After deployment is finished, users can clean resources (NS, VNFD, http client and server) with ns-clean.sh script.

$ cd ~/tacker/contrib/tacker-config
$ ./ns-clean.sh

Reference

1

https://www.etsi.org/deliver/etsi_gs/NFV-IFA/001_099/014/02.01.01_60/gs_NFV-IFA014v020101p.pdf

2

https://wiki.onap.org/display/DW/ONAP+Release+1+modeling+specification?preview=%2F13599755%2F13599839%2FNSD+Specification.pdf

3

https://github.com/openstack/tacker/blob/master/tacker/nfvo/drivers/workflow/workflow_generator.py

4

https://docs.openstack.org/tacker/latest/install/deploy_openwrt.html

5

https://docs.openstack.org/tacker/latest/user/vnffg_usage_guide.html

6

https://docs.openstack.org/tacker/latest/user/vnffg_usage_guide_advanced.html

7

https://github.com/openstack/tacker/blob/master/samples/tosca-templates/nsd/sample-tosca-vnfd1.yaml

8

https://github.com/openstack/tacker/blob/master/samples/tosca-templates/nsd/sample-tosca-vnfd2.yaml