Interfaces

The BNG Blaster supports three types of interfaces.

All interfaces are optional but obviously at least one interface is required to start the BNG Blaster.

Interface Settings

The following settings are applied to all interfaces.

{
    "interfaces": {
        "tx-interval": 0.1,
        "rx-interval": 0.1,
        "io-slots": 2048,
    }
}

{ "interfaces": {} }

Attribute	Description	Default
tx-interval	TX ring polling interval in milliseconds	1.0
rx-interval	RX ring polling interval in milliseconds	1.0
qdisc-bypass	Bypass the kernel’s qdisc layer	true
io-mode	IO mode	packet_mmap_raw
io-slots	IO slots (ring size)	4096
io-stream-max-ppi	IO traffic stream max packets per interval	32
capture-include-streams	Include traffic streams in capture	true
mac-modifier	Third byte of access session MAC address (0-255)	0

The tx-interval and rx-interval should be set to at to at least 1.0 (1ms) if more precise timestamps or high throughput is needed. This is recommended for IGMP join/leave or QoS delay measurements. For higher packet rates (>1g) it might be needed to increase the io-slots from the default value of 4096.

The supported IO modes are listed with bngblaster -v but except packet_mmap_raw all other modes are currently considered as experimental. In the default mode (packet_mmap_raw) all packets are received in a Packet MMAP ring buffer and send directly trough RAW packet sockets.

The BNG Blaster implements all protocols in userspace. Therefore the user interfaces must not have an IP address configured in the host operating system, to prevent the received packets are handled by Kernel.

All used interfaces must be in an operational state up.

sudo ip link set dev <interface> up

It is not possible to send packets larger than the interface MTU which is 1500 per default but for PPPoE with multiple VLAN headers this might be not enough for large packets. Therefore the interface MTU should be increased using the following commands.

sudo ip link set mtu 9000 dev <interface>

This can be also archived via netplan using the following configuration for each BNG Blaster interface.

network:
version: 2
renderer: networkd
ethernets:
    eth1:
    dhcp4: no
    dhcp6: no
    link-local: []
    mtu: 9000
    eth2:
    dhcp4: no
    dhcp6: no
    link-local: []
    mtu: 9000

Note

The number of interfaces is currently limited to 32!

It might be also needed to increase the hardware and software queue size of your network interfaces for higher throughput.

The command ethtool -g <interface> shows the currently applied and maximum hardware queue size.

$ sudo ethtool -g ens5f1
Ring parameters for ens5f1:
Pre-set maximums:
RX:             4096
RX Mini:        0
RX Jumbo:       0
TX:             4096
Current hardware settings:
RX:             512
RX Mini:        0
RX Jumbo:       0
TX:             512

The currently applied settings can be change with the following command:

sudo ethtool -G ens5f1 tx 4096 rx 4096

You can even change the software queue size:

sudo ip link set txqueuelen 4096 dev ens5f1

Note

Today all traffic is received in main thread, therefore the single thread performance of your CPU is the most significant performance factor.

Network Interfaces

The network interfaces are used for traffic and routing protocols.

Those interfaces can communicate with the configured gateway only. Meaning that all traffic sent from the network interface will be sent to the learned MAC address of the configured gateway.

The network interface behaves like a router. It accepts all traffic sent to its own MAC address. This allows to send and receive traffic for prefixes advertised via routing protocols or configured via static routes on the connected device under test.

The BNG Blaster responds to all ICMP echo requests sent to its own MAC address.

{ "interfaces": { "network": [] } }

Attribute	Description	Default
interface	Network interface name (e.g. eth0, …)
address	Local network interface IPv4 address
gateway	Gateway network interface IPv4 address
address-ipv6	Local network interface IPv6 address (implicitly /64)
gateway-ipv6	Gateway network interface IPv6 address (implicitly /64)
vlan	Network interface VLAN	0 (untagged)
gateway-mac	Optional set gateway MAC address manually
gateway-resolve-wait	Sessions will not start until gateways are resolved	true
isis-instance-id	Assign interface to ISIS instance
isis-level	ISIS interface level	3
isis-p2p	ISIS P2P interface	true
isis-l1-metric	ISIS level 1 interface metric	10
isis-l2-metric	ISIS level 2 interface metric	10

The BNG Blaster supports multiple network interfaces as shown in the example below.

{
    "interfaces": {
        "tx-interval": 1,
        "rx-interval": 1,
        "io-slots": 4096,
        "network": [
            {
                "interface": "eth2",
                "address": "10.0.0.1",
                "gateway": "10.0.0.2",
                "address-ipv6": "fc66:1337:7331::1",
                "gateway-ipv6": "fc66:1337:7331::2"
            },
            {
                "interface": "eth3",
                "address": "10.0.1.1",
                "gateway": "10.0.1.2",
                "address-ipv6": "fc66:1337:7331:1::1",
                "gateway-ipv6": "fc66:1337:7331:1::2"
            }
        ],
    }
}

Using multiple network interfaces requires to select which network interface to be used. If not explicitly configured one of the interface is selected automatically. Therefore, the configuration option network-interface is supported in different sections.

Access Interfaces

The access interfaces are used to emulate PPPoE and IPoE clients.

{ "interfaces": { "access": [] } }

Attribute	Description	Default
interface	Access interface name (e.g. eth0, …)
network-interface	Select the corresponding network interface for this session
type	Set access type (pppoe or ipoe)	pppoe
vlan-mode	Set VLAN mode 1:1 or N:1	1:1
qinq	Set outer VLAN ethertype to QinQ (0x88a8)	false
outer-vlan-min	Outer VLAN minimum value	0 (untagged)
outer-vlan-max	Outer VLAN maximum value	0 (untagged)
outer-vlan	Set outer-vlan-min/max equally
inner-vlan-min	Inner VLAN minimum value	0 (untagged)
inner-vlan-max	Inner VLAN maximum value	0 (untagged)
inner-vlan	Set inner-vlan-min/max equally
third-vlan	Add a fixed third VLAN (most inner VLAN)	0 (untagged)
address	Static IPv4 base address (IPoE only)
ppp-mru	Overwrite PPP MRU (PPPoE only)
address-iter	Static IPv4 base address iterator (IPoE only)
gateway	Static IPv4 gateway address (IPoE only)
gateway-iter	Static IPv4 gateway address iterator (IPoE only)
username	Overwrite the username from authentication section
password	Overwrite the password from authentication section
authentication-protocol	Overwrite the username from authentication section
agent-circuit-id	Overwrite the agent-circuit-id from access-line section
agent-remote-id	Overwrite the agent-remote-id from access-line section
rate-up	Overwrite the rate-up from access-line section
rate-down	Overwrite the rate-down from access-line section
dsl-type	Overwrite the dsl-type from access-line section
ipcp	De-/activate PPP IPCP
ip6cp	De-/activate PPP IP6CP
ipv4	De-/activate IPoE IPv4
ipv6	De-/activate IPoE IPv6
dhcp	De-/activate DHCP
dhcpv6	De-/activate DHCPv6
igmp-autostart	Overwrite IGMP autostart
igmp-version	Overwrite IGMP protocol version (1, 2 or 3)
stream-group-id	Stream group identifier
access-line-profile-id	Access-line-profile identifier
cfm-cc	De-/activate EOAM CFM CC (IPoE only)	false
cfm-level	Set EOAM CFM maintenance domain level	0
cfm-ma-id	Set EOAM CFM maintenance association identifier	0
cfm-ma-name	Set EOAM CFM maintenance association short name
i1-start	Iterator for usage in strings {i1}	1
i1-step	Iterator step per session	1
i2-start	Iterator for usage in strings {i2}	1
i2-step	Iterator step per session	1
monkey	Enable monkey testing	false

For all modes, it is possible to configure between zero and three VLAN tags on the access interface. The VLAN identifier 0 disables the corresponding VLAN header.

[ethernet][outer-vlan][inner-vlan][third-vlan][pppoe]...

Untagged

{
    "access": {
        "interface": "eth1",
        "outer-vlan-min": 0,
        "outer-vlan-max": 0,
        "inner-vlan-min": 0,
        "inner-vlan-max": 0
    }
}

Single Tagged

{
    "access": {
        "interface": "eth1",
        "outer-vlan-min": 1,
        "outer-vlan-max": 4049,
        "inner-vlan-min": 0,
        "inner-vlan-max": 0
    }
}

Double Tagged

{
    "access": {
        "interface": "eth1",
        "outer-vlan-min": 1,
        "outer-vlan-max": 4049,
        "inner-vlan-min": 7,
        "inner-vlan-max": 7
    }
}

Triple Tagged

{
    "access": {
        "interface": "eth1",
        "outer-vlan-min": 10,
        "outer-vlan-max": 20,
        "inner-vlan-min": 128,
        "inner-vlan-max": 4000,
        "third-vlan": 7
    }
}

The BNG Blaster supports also multiple access interfaces or VLAN ranges as shown in the example below.

{
    "access": [
        {
            "interface": "eth1",
            "type": "pppoe",
            "username": "pta@rtbrick.com",
            "outer-vlan-min": 1000,
            "outer-vlan-max": 1999,
            "inner-vlan-min": 7,
            "inner-vlan-max": 7
        },
        {
            "interface": "eth1",
            "type": "pppoe",
            "username": "l2tp@rtbrick.com",
            "outer-vlan-min": 2000,
            "outer-vlan-max": 2999,
            "inner-vlan-min": 7,
            "inner-vlan-max": 7
        },
        {
            "interface": "eth3",
            "type": "pppoe",
            "username": "test@rtbrick.com",
            "outer-vlan-min": 128,
            "outer-vlan-max": 4000,
            "inner-vlan-min": 7,
            "inner-vlan-max": 7
        },
        {
            "interface": "eth4",
            "type": "ipoe",
            "outer-vlan-min": 8,
            "outer-vlan-max": 9,
            "address": "200.0.0.1",
            "address-iter": "0.0.0.4",
            "gateway": "200.0.0.2",
            "gateway-iter": "0.0.0.4"
        }
    ]
}

The configuration attributes for username, agent-remote-id and agent-circuit-id support also some variable substitution. The variable {session-global} will be replaced with a number starting from 1 and incremented for every new session. where as the variable {session} is incremented per interface section.

In VLAN mode N:1 only one VLAN combination is supported per access interface section. This means that only VLAN min or max is considered as VLAN identifier.

{
    "access": [
        {
            "interface": "eth1",
            "type": "pppoe",
            "vlan-mode": "N:1",
            "username": "test@rtbrick.com",
            "outer-vlan-min": 7
        },
        {
            "interface": "eth2",
            "type": "pppoe",
            "vlan-mode": "N:1",
            "username": "test@rtbrick.com",
            "outer-vlan-min": 2000,
            "inner-vlan-min": 7,
        },
    ]
}

A10NSP Interfaces

The A10NSP interface emulates an layer two provider interface. The term A10 refers to the end-to-end ADSL network reference model from TR-025.

The A10NSP interface is required for L2BSA tests.

{ "interfaces": { "a10nsp": [] } }

Attribute	Description	Default
interface	A10nSP interface name (e.g. eth0, …)
qinq	Set outer VLAN ethertype to QinQ (0x88a8)	false
mac	Optional set gateway interface address manually

The BNG Blaster supports multiple A10NSP interfaces as shown in the example below.

{
    "interfaces": {
        "tx-interval": 1,
        "rx-interval": 1,
        "a10nsp": [
            {
                "interface": "eth4",
                "qinq": true,
                "mac": "02:00:00:ff:ff:01"
            },
            {
                "interface": "eth5",
                "qinq": false,
                "mac": "02:00:00:ff:ff:02"
            }
        ],
    }
}

You can define multiple interfaces with the same MAC address to emulate some static link aggregation (without LACP).