Currently Neutron does not support service function chaining. To support service function chaining, Service VMs must be attached at points in the network and then traffic must be steered between these attachment points. Please refer to Neutron Service Chain blue-print and Bugs [1] [2] related to this specification for more information.
All Neutron network services and VMs are connected to a Neutron network via Neutron ports. This makes it possible to create a traffic steering model for service chaining that uses only Neutron ports. This traffic steering model has no notion of the actual services attached to these Neutron ports.
The service VM hosting the service functions is instantiated and configured, then VNICs are added to the VM and then these VNICs are attached to the network by Neutron ports. Once the service function is attached to Neutron ports, the ports may be included in a “port chain” to allow the service function to provide treatment to the user’s traffic.
A Port Chain (Service Function Path) consists of:
If a service function has a pair of ports, the first port in the port-pair is the ingress port of the service function, and the second port is the egress port of the service function. If a service function has one bidirectional port, then both ports in the port-pair have the same value. A Port Chain is a directional service chain. The first port of the first port-pair is the head of the service chain. The second port of the last port-pair is the tail of the service chain. A bidirectional service chain would be composed of two unidirectional Port Chains.
For example, [{‘p1’: ‘p2’}, {‘p3’: ‘p4’}, {‘p5’: ‘p6’}] represents:
+------+ +------+ +------+
| SF1 | | SF2 | | SF3 |
+------+ +------+ +------+
p1| |p2 p3| |p4 p5| |p6
| | | | | |
->---+ +---------+ +----------+ +---->
where p1 is the head of the Port Chain and p6 is the tail of the Port Chain, and SF1 has ports p1 and p2, SF2 has ports p3 and p4, and SF3 has ports p5 and p6.
In order to create a chain, the user needs to have the actual port objects. The work flow would typically be:
The sequence of 2. and 3. can be switched.
A SF’s Neutron port may be associated with more than one Port Chain to allow a service function to be shared by multiple chains.
If there is more than one service function instance of a specific type available to meet the user’s service requirement, their Neutron ports are included in the port chain as a sub-list. For example, if {p3, p4}, {p7, p8} are the port-pairs of two FW instances, they both may be included in a port chain for load distribution as shown below.
[{‘p1’: ‘p2’}, [{‘p3’: ‘p4’},{‘p7’: ‘p8’}], {‘p5’: ‘p6’}]
Flow classifiers are used to select the traffic that can access the chain. Traffic that matches any flow classifier will be directed to the first port in the chain. The flow classifier will be a generic independent module and may be used by other projects like FW, QOS, etc.
A flow classifier cannot be part of two different port-chains otherwise ambiguity will arise as to which chain path that flow’s packets should go. A check will be made to ensure no ambiguity. But multiple flow classifiers can be associated with a port chain since multiple different types of flows can request the same service treatment path.
CLI Commands
Syntax:
neutron port-pair-create [-h]
[--description <description>]
--ingress <port-id>
--egress <port-id>
[--service-function-parameters <parameter>] PORT-PAIR-NAME
neutron port-pair-group-create [-h]
[--description <description>]
--port-pairs <port-pair-id>
[--port-pair-group-parameters <parameter>] PORT-PAIR-GROUP-NAME
neutron flow-classifier-create [-h]
[--description <description>]
[--protocol <protocol>]
[--ethertype <Ethertype>]
[--source-port <Minimum source protocol port>:<Maximum source protocol port>]
[--destination-port <Minimum destination protocol port>:<Maximum destination protocol port>]
[--source-ip-prefix <Source IP prefix>]
[--destination-ip-prefix <Destination IP prefix>]
[--logical-source-port <Neutron source port>]
[--logical-destination-port <Neutron destination port>]
[--l7-parameters <L7 parameter>] FLOW-CLASSIFIER-NAME
neutron port-chain-create [-h]
[--description <description>]
--port-pair-group <port-pair-group-id>
[--flow-classifier <classifier-id>]
[--chain-parameters <chain-parameter>] PORT-CHAIN-NAME
1. neutron port-chain-create The port-chain-create returns the ID of the Port Chain.
Each “port-pair-group” option specifies a type of SF. If a chain consists of a sequence of different types of SFs, then the chain will have multiple “port-pair-group”s. There must be at least one “port-pair-group” in the Port Chain.
The “flow-classifier” option may be repeated to associate multiple flow classifiers with a port chain, with each classifier identifying a flow. If the flow-classifier is not specified, then no traffic will be steered through the chain.
One chain parameter option is currently defined. More parameter options can be added in future extensions to accommodate new requirements. The “correlation” parameter is used to specify the type of chain correlation mechanism. This parameter allows different correlation mechanisms to be selected. This will be set to “mpls” for now to be consistent with current OVS capability. If this parameter is not specified, it will default to “mpls”.
The port-chain-create command returns the ID of a Port chain.
A port chain can be created, read, updated and deleted, and when a chain is created/read/updated/deleted, the options that are involved would be based on the CRUD in the “Port Chain” resource table below.
2. neutron port-pair-group-create Inside each “port-pair-group”, there could be one or more port-pairs. Multiple port-pairs may be included in a “port-pair-group” to allow the specification of a set of functionally equivalent SFs that can be be used for load distribution, i.e., the “port-pair” option may be repeated for multiple port-pairs of functionally equivalent SFs.
The port-pair-group-create command returns the ID of a Port Pair group.
3. neutron port-pair-create A Port Pair represents a service function instance. The ingress port and the egress port of the service function may be specified. If a service function has one bidirectional port, the ingress port has the same value as the egress port. The “service-function-parameter” option allows the passing of SF specific parameter information to the data path. These include:
- The “correlation” parameter is used to specify the type of chain correlation mechanism supported by a specific SF. This is needed by the data plane switch to determine how to associate a packet with a chain. This will be set to “none” for now since there is no correlation mechanism supported by the SF. In the future, it can be extended to include “mpls”, “nsh”, etc.. If this parameter is not specified, it will default to “none”.
- The “weight” parameter is used to specify the weight for each SF for load distribution in a port pair group. This represents a percentage of the traffic to be sent to each SF.
The port-pair-create command returns the ID of a Port Pair.
4. neutron flow-classifier-create A combination of the “source” options defines the source of the flow. A combination of the “destination” options defines the destination of the flow. The l7_parameter is a place-holder that may be used to support flow classification using L7 fields, such as URL. If an option is not specified, it will default to wildcard value except for ethertype which defaults to ‘IPv4’, for logical-source-port and logical-destination-port which defaults to none.
The flow-classifier-create command returns the ID of a flow classifier.
Data model:
+-------+ +----------+ +------------+
| Port |--------| Port Pair|--------| Port Pairs |
| Chain |* *| Groups | 1 *| |
+-------+ +----------+ +------------+
|1
|
|*
+--------------+
| Flow |
| Classifiers |
+--------------+
New objects:
Port Chain Operations:
| Operation | URL | Description |
|---|---|---|
| POST | /sfc/port_chains | Create a Port Chain |
| PUT | /sfc/port_chains/{chain_id} | Update a specific Port Chain |
| DELETE | /sfc/port_chains/{chain_id} | Delete a specific Port Chain |
| GET | /sfc/port_chains | List all Port Chains for specified tenant |
| GET | /sfc/port_chains/{chain_id} | Show information for a specific Port Chain |
Port Pair Group Operations:
| Operation | URL | Description |
|---|---|---|
| POST | /sfc/port_pair_groups | Create a Port Pair Group |
| PUT | /sfc/port_pair_groups/{group_id} | Update a specific Port Pair Group |
| DELETE | /sfc/port_pair_groups/{group_id} | Delete a specific Port Pair Group |
| GET | /sfc/port_pair_groups | List all Port Pair Groups for specified tenant |
| GET | /sfc/port_pair_groups/{group_id} | Show information for a specific Port Pair |
Port Pair Operations:
| Operation | URL | Description |
|---|---|---|
| POST | /sfc/port_pairs | Create a Port Pair |
| PUT | /sfc/port_pairs/{pair_id} | Update a specific Port Pair |
| DELETE | /sfc/port_pairs/{pair_id} | Delete a specific Port Pair |
| GET | /sfc/port_pairs | List all Port Pairs for specified tenant |
| GET | /sfc/port_pairs/{pair_id} | Show information for a specific Port Pair |
Flow Classifier Operations:
| Operation | URL | Description |
|---|---|---|
| POST | /sfc/flow_classifiers | Create a Flow-classifier |
| PUT | /sfc/flow_classifiers/{flow_id} | Update a specific Flow-classifier |
| DELETE | /sfc/flow_classifiers/{flow_id} | Delete a specific Flow-classifier |
| GET | /sfc/flow_classifiers | List all Flow-classifiers for specified tenant |
| GET | /sfc/flow_classifiers/{flow_id} | Show information for a specific Flow-classifier |
The following new resources will be created as a result of the API handling.
Port Chain resource:
| Attribute Name | Type | Access | Default Value | CRUD | Description |
|---|---|---|---|---|---|
| id | uuid | RO, all | generated | R | Port Chain ID. |
| tenant_id | uuid | RO, all | from auth token | CR | Tenant ID. |
| name | string | RW, all | ‘’ | CRU | Port Chain name. |
| description | string | RW, all | ‘’ | CRU | Port Chain description. |
| port_pair_groups | list(uuid) | RW, all | N/A | CRU | List of port-pair-groups. |
| flow_classifiers | list(uuid) | RW, all | [] | CRU | List of flow-classifiers. |
| chain_parameters | dict | RW, all | mpls | CR | Dict. of parameters: ‘correlation’:String |
| chain_id | integer | RW, all | Any | CR | Data-plane Chain Path ID. |
The data-plane chain path ID is normally generated by the data-plane implementation. However, an application may optionally generate its own data-plane chain path ID and apply it to the Port Chain using the chain_id attribute.
Port Pair Group resource:
| Attribute Name | Type | Access | Default Value | CRUD | Description |
|---|---|---|---|---|---|
| id | uuid | RO, all | generated | R | Port pair group ID. |
| tenant_id | uuid | RO, all | from auth token | CR | Tenant ID. |
| name | string | RW, all | ‘’ | CRU | Port pair group name. |
| description | string | RW, all | ‘’ | CRU | Port pair group description. |
| port_pairs | list | RW, all | N/A | CRU | List of port-pairs. |
| port_pair_group _parameters | dict | RW, all | ‘’ | CR | Dict. of parameters: ‘lb_fields’:String ‘service_type’:String |
Port Pair resource:
| Attribute Name | Type | Access | Default | CRUD | Description |
|---|---|---|---|---|---|
| id | uuid | RO, all | generated | R | Port pair ID. |
| tenant_id | uuid | RO, all | from auth token | CR | Tenant ID. |
| name | string | RW, all | ‘’ | CRU | Port pair name. |
| description | string | RW, all | ‘’ | CRU | Port pair description. |
| ingress | uuid | RW, all | N/A | CR | Ingress port ID. |
| egress | uuid | RW, all | N/A | CR | Egress port ID. |
| service_function_parameters | dict | RW, all | None | CR | Dict. of parameters: ‘correlation’:String ‘weight’:Integer |
Flow Classifier resource:
| Attribute Name | Type | Access | Default Value | CRUD | Description |
|---|---|---|---|---|---|
| id | uuid | RO, all | generated | R | Flow-classifier ID. |
| tenant_id | uuid | RO, all | from auth token | CR | Tenant ID. |
| name | string | RW, all | ‘’ | CRU | Flow-classifier name. |
| description | string | RW, all | ‘’ | CRU | Flow-classifier description. |
| ethertype | string | RW, all | ‘IPv4’ | CR | L2 ethertype. Can be ‘IPv4’ or ‘IPv6’ only. |
| protocol | string | RW, all | Any | CR | IP protocol name. |
| source_port_range_min | integer | RW, all | Any | CR | Minimum source protocol port. |
| source_port_range_max | integer | RW, all | Any | CR | Maximum source protocol port. |
| destination_port_range_min | integer | RW, all | Any | CR | Minimum destination protocol port. |
| destination_port_range_max | integer | RW, all | Any | CR | Maximum destination protocol port. |
| source_ip_prefix | CIDR | RW, all | Any | CR | Source IPv4 or IPv6 prefix. |
| destination_ip_prefix | CIDR | RW, all | Any | CR | Destination IPv4 or IPv6 prefix. |
| logical_source_port | uuid | RW, all | None | CR | Neutron source port. |
| logical_destination_port | uuid | RW, all | None | CR | Neutron destination port. |
| l7_parameters | dict | RW, all | Any | CR | Dict. of L7 parameters. |
Json Port-pair create request example:
{"port_pair": {"name": "SF1",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Firewall SF instance",
"ingress": "dace4513-24fc-4fae-af4b-321c5e2eb3d1",
"egress": "aef3478a-4a56-2a6e-cd3a-9dee4e2ec345",
}
}
{"port_pair": {"name": "SF2",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Loadbalancer SF instance",
"ingress": "797f899e-73d4-11e5-b392-2c27d72acb4c",
"egress": "797f899e-73d4-11e5-b392-2c27d72acb4c",
}
}
Json Port-pair create response example:
{"port_pair": {"name": "SF1",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Firewall SF instance",
"ingress": "dace4513-24fc-4fae-af4b-321c5e2eb3d1",
"egress": "aef3478a-4a56-2a6e-cd3a-9dee4e2ec345",
"id": "78dcd363-fc23-aeb6-f44b-56dc5e2fb3ae",
}
}
{"port_pair": {"name": "SF2",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Loadbalancer SF instance",
"ingress": "797f899e-73d4-11e5-b392-2c27d72acb4c",
"egress": "797f899e-73d4-11e5-b392-2c27d72acb4c",
"id": "d11e9190-73d4-11e5-b392-2c27d72acb4c"
}
}
Json Port Pair Group create request example:
{"port_pair_group": {"name": "Firewall_PortPairGroup",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Grouping Firewall SF instances",
"port_pairs": [
"78dcd363-fc23-aeb6-f44b-56dc5e2fb3ae"
],
"port_pair_group_parameters": [
"lb_fields: ip_src"
]
}
}
{"port_pair_group": {"name": "Loadbalancer_PortPairGroup",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Grouping Loadbalancer SF instances",
"port_pairs": [
"d11e9190-73d4-11e5-b392-2c27d72acb4c"
]
"port_pair_group_parameters": [
"lb_fields: ip_src"
]
}
}
Json Port Pair Group create response example:
{"port_pair_group": {"name": "Firewall_PortPairGroup",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Grouping Firewall SF instances",
"port_pairs": [
"78dcd363-fc23-aeb6-f44b-56dc5e2fb3ae
],
"port_pair_group_parameters": [
"lb_fields: ip_src"
]
"id": "4512d643-24fc-4fae-af4b-321c5e2eb3d1",
}
}
{"port_pair_group": {"name": "Loadbalancer_PortPairGroup",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Grouping Loadbalancer SF instances",
"port_pairs": [
"d11e9190-73d4-11e5-b392-2c27d72acb4c"
],
"port_pair_group_parameters": [
"lb_fields: ip_src"
]
"id": "4a634d49-76dc-4fae-af4b-321c5e23d651",
}
}
Json Flow Classifier create request example:
{"flow_classifier": {"name": "FC1",
"tenant_id": "1814726e2d22407b8ca76db5e567dcf1",
"description": "Flow rule for classifying TCP traffic",
"protocol": "TCP",
"source_port_range_min": 22, "source_port_range_max": 4000,
"destination_port_range_min": 80, "destination_port_range_max": 80,
"source_ip_prefix": null, "destination_ip_prefix": "22.12.34.45"
}
}
{"flow_classifier": {"name": "FC2",
"tenant_id": "1814726e2d22407b8ca76db5e567dcf1",
"description": "Flow rule for classifying UDP traffic",
"protocol": "UDP",
"source_port_range_min": 22, "source_port_range_max": 22,
"destination_port_range_min": 80, "destination_port_range_max": 80,
"source_ip_prefix": null, "destination_ip_prefix": "22.12.34.45"
}
}
Json Flow Classifier create response example:
{"flow_classifier": {"name": "FC1",
"tenant_id": "1814726e2d22407b8ca76db5e567dcf1",
"description": "Flow rule for classifying TCP traffic",
"protocol": "TCP",
"source_port_range_min": 22, "source_port_range_max": 4000,
"destination_port_range_min": 80, "destination_port_range_max": 80,
"source_ip_prefix": null , "destination_ip_prefix": "22.12.34.45",
"id": "4a334cd4-fe9c-4fae-af4b-321c5e2eb051"
}
}
{"flow_classifier": {"name": "FC2",
"tenant_id": "1814726e2d22407b8ca76db5e567dcf1",
"description": "Flow rule for classifying UDP traffic",
"protocol": "UDP",
"source_port_range_min": 22, "source_port_range_max": 22,
"destination_port_range_min": 80, "destination_port_range_max": 80,
"source_ip_prefix": null , "destination_ip_prefix": "22.12.34.45",
"id": "105a4b0a-73d6-11e5-b392-2c27d72acb4c"
}
}
Json Port Chain create request example:
{"port_chain": {"name": "PC1",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Steering TCP and UDP traffic first to Firewall and then to Loadbalancer",
"flow_classifiers": [
"4a334cd4-fe9c-4fae-af4b-321c5e2eb051",
"105a4b0a-73d6-11e5-b392-2c27d72acb4c"
],
"port_pair_groups": [
"4512d643-24fc-4fae-af4b-321c5e2eb3d1",
"4a634d49-76dc-4fae-af4b-321c5e23d651"
],
"chain_id": "10034"
}
}
Json Port Chain create response example:
{"port_chain": {"name": "PC2",
"tenant_id": "d382007aa9904763a801f68ecf065cf5",
"description": "Steering TCP and UDP traffic first to Firewall and then to Loadbalancer",
"flow_classifiers": [
"4a334cd4-fe9c-4fae-af4b-321c5e2eb051",
"105a4b0a-73d6-11e5-b392-2c27d72acb4c"
],
"port_pair_groups": [
"4512d643-24fc-4fae-af4b-321c5e2eb3d1",
"4a634d49-76dc-4fae-af4b-321c5e23d651"
],
"chain_id": "10034",
"id": "1278dcd4-459f-62ed-754b-87fc5e4a6751"
}
}