Interfaces

The BNG Blaster distinguishes between interface links and interface functions. An interface link can be considered as the actual interface with all the corresponding IO settings. This is similar but not the same as physical interfaces in typical router implementations. Interface functions are similar to logical interfaces and define the actual services. One or more interface functions can be attached to each interface link.

At least one interface function is required to start the BNG Blaster.

Operating System Settings

The BNG Blaster implements all protocols in user space. Therefore the used interfaces links must not have an IP address configured in the host operating system, to prevent that the received packets are handled or even responded to from the Linux kernel as well.

All used interface links must be in an operational state up.

sudo ip link set dev <interface> up

It is not possible to send packets larger than the configured interface MTU, which is 1500 bytes per default. 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>

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

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

It might be also needed to increase the hardware and software queue size of your network interface links 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 changed 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

Interface Settings

The interfaces section contains all configurations around interface links and options.

{ "interfaces": {} }

Attribute

Description

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

io-slots
IO slots (ring size).
It might be also needed to increase the io-slots to
reach the desired throughput. The actual meaning of IO slots
depends on the selected IO mode. For Packet MMAP, it defines the
maximum number of packets in the ring buffer.
Default: 4096

io-burst
IO burst (packets).
Default: 256 Range: 1 to 65535

qdisc-bypass
Bypass the kernel’s qdisc layer.
It’s currently not recommended to change the default (issue #206)!
Default: true

tx-interval
TX polling interval in milliseconds.
Default: 0.1 Range: 0.0001 to 1000

rx-interval
RX polling interval in milliseconds.
Default: 0.1 Range: 0.0001 to 1000

tx-threads
Number of TX threads per interface link.
Default: 0 (main thread)

rx-threads
Number of RX threads per interface link.
Default: 0 (main thread)

capture-include-streams
Include traffic streams in the capture.
Default: false

mac-modifier
Third byte of access session MAC address (0-255). This option
allows to run multiple BNG Blaster instances with disjoint session
MAC addresses.
Default: 0
 
{
    "interfaces": {
        "tx-interval": 0.1,
        "rx-interval": 0.1,
        "io-slots": 4096,
    }
}

Interface Functions

The BNG Blaster supports three types of interface functions, network, access, and a10nsp.

BNG Blaster Interfaces

Network Interfaces

The network interfaces are used to emulate the core-facing side of the internet with optional routing protocols and traffic.

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 sending and receiving traffic for prefixes advertised via routing protocols or configured via static routes on the connected device under test.

The network interfaces are also used to inject downstream multicast test traffic for IPTV tests. It is also possible to send RAW traffic streams between network interfaces without any access interface defined for non-BNG testing.

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

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

Attribute

Description

interface
Parent interface/link name (e.g. eth0, …).

address
Local IPv4 address (e.g. 10.0.0.1/24).

gateway
Default gateway IPv4 address.

address-ipv6
Local IPv6 address (e.g. fc66::1/64).

gateway-ipv6
Default gateway IPv6 address.

ipv6-router-advertisement
Send IPv6 router advertisements (ICMPv6 RA).
Default: true

mtu
MTU size.
Default: 1500 Range: 64 - 9000

vlan
Network interface VLAN.
Default: 0 (untagged)

gateway-mac
Optional set default gateway MAC address manually. Per default
this MAC address is resolved via ARP/ND.

gateway-resolve-wait
Sessions and protocols will not start until gateways are resolved.
Default: true

isis-instance-id
Assign the interface to an ISIS instance.

isis-level
ISIS interface level.
Default: 3 Range: 1 - 3

isis-p2p
ISIS P2P interface.
Default: true

isis-l1-metric
ISIS level 1 interface metric.
Default: 10

isis-l2-metric
ISIS level 2 interface metric.
Default: 10

isis-l1-priority
ISIS level 1 interface priority.
Default: 10

isis-l2-priority
ISIS level 2 interface priority.
Default: 10

ospfv2-instance-id
Assign the interface to an OSPFv2 instance.

ospfv2-type
OSPFv2 interface type (p2p or broadcast).
Default: broadcast

ospfv2-metric
OSPFv2 interface metric.
Default: 10

ospfv3-instance-id
Assign the interface to an OSPFv3 instance.

ospfv3-type
OSPFv3 interface type (p2p or broadcast).
Default: broadcast

ospfv3-metric
OSPFv3 interface metric.
Default: 10

ldp-instance-id
Assign the interface to a LDP instance.

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

{
    "interfaces": {
        "network": [
            {
                "interface": "eth2",
                "address": "10.0.0.1/24",
                "gateway": "10.0.0.2",
                "address-ipv6": "fc66:1337:7331::1/64",
                "gateway-ipv6": "fc66:1337:7331::2"
            },
            {
                "interface": "eth3",
                "address": "10.0.1.1/24",
                "gateway": "10.0.1.2",
                "address-ipv6": "fc66:1337:7331:1::1/64",
                "gateway-ipv6": "fc66:1337:7331:1::2"
            }
        ],
    }
}

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

It is also supported to have multiple VLAN-tagged network interfaces on the same interface link.

VLAN-tagged network interfaces must be referenced by <interface>:<vlan> in the configuration to distinguish between them.

{
    "interfaces": {
        "network": [
            {
                "interface": "eth1",
                "address": "10.100.0.2/24",
                "gateway": "10.100.0.1",
                "vlan": 100
            },
            {
                "interface": "eth1",
                "address": "10.200.0.2/24",
                "gateway": "10.200.0.1",
                "vlan": 200
            }
        ]
    },
    "streams": [
        {
            "name": "S100",
            "type": "ipv4",
            "pps": 10,
            "network-interface": "eth1:100",
            "destination-ipv4-address": "10.200.0.2"
        },
        {
            "name": "S200",
            "type": "ipv4",
            "pps": 20,
            "network-interface": "eth1:200",
            "destination-ipv4-address": "10.100.0.2"
        }
    ]
}

Access Interfaces

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

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

Attribute

Description

interface
Parent interface/link name (e.g. eth0, …).

network-interface
Select the corresponding network interface for those sessions.
Default: first network interface from configuration

a10nsp-interface
Select the corresponding A10NSP interface for those sessions.
Default: first a10nsp interface from configuration

type
Set access type (pppoe or ipoe).
Default: pppoe

vlan-mode
Set VLAN mode to 1:1 or N:1.
Default: 1:1

qinq
Set outer VLAN ethertype to QinQ (0x88a8).
Default: false

outer-vlan-min
Outer VLAN minimum value.
Default: 0 (untagged)

outer-vlan-max
Outer VLAN maximum value.
Default: 0 (untagged)

outer-vlan-step
Outer VLAN step (iterator).
Default: 1

outer-vlan
Set outer-vlan-min/max equally.

inner-vlan-min
Inner VLAN minimum value.
Default: 0 (untagged)

inner-vlan-max
Inner VLAN maximum value.
Default: 0 (untagged)

inner-vlan-step
Inner VLAN step (iterator).
Default: 1

inner-vlan
Set inner-vlan-min/max equally.

third-vlan
Add a static third VLAN (most inner VLAN).
Default: 0 (untagged)

ipv4
Set false to deactivate IPv4.

ipv6
Set false to deactivate IPv6.

address
Static IPv4 base address (IPoE only).

address-iter
Static IPv4 base address iterator (IPoE only).
Default: 0.0.0.0

gateway
Static IPv4 gateway address (IPoE only).

gateway-iter
Static IPv4 gateway address iterator (IPoE only).
Default: 0.0.0.0

cfm-cc
Enable EOAM CFM CC (IPoE only).
Default: false

cfm-level
Set EOAM CFM maintenance domain level.
Default: 0 Range: 0 - 7

cfm-ma-id
Set EOAM CFM maintenance association identifier.
Default: 0 Range: 0 - 65535

cfm-ma-name
Set EOAM CFM maintenance association short name (string).

username
Overwrite the username from the authentication section.

password
Overwrite the password from the authentication section.

authentication-protocol
Overwrite the username from the authentication section.

agent-circuit-id
Overwrite the agent-circuit-id from the access-line section.

agent-remote-id
Overwrite the agent-remote-id from the access-line section.

access-aggregation-circuit-id
Overwrite the access-aggregation-circuit-id from the
access-line section.

rate-up
Overwrite the rate-up from the access-line section.

rate-down
Overwrite the rate-down from the access-line section.

dsl-type
Overwrite the dsl-type from the access-line section.

ppp-mru
Overwrite PPP MRU (PPPoE only).

ipcp
Overwrite PPP IPCP enable option (PPPoE only).

ip6cp
Overwrite PPP IP6CP enable option (PPPoE only).

dhcp
Overwrite DHCP enable option.

dhcpv6
Overwrite DHCPv6 enable option.

dhcpv6-ldra
Overwrite DHCPv6 LDRA option.

igmp-autostart
Overwrite IGMP autostart option.

igmp-version
Overwrite IGMP protocol version (1, 2, or 3).

session-group-id
Set session group identifier.
Default: 0 Range: 0 - 65535

stream-group-id
Set stream group identifier.
Default: 0 Range: 0 - 65535

access-line-profile-id
Set access-line-profile identifier.
Default: 0 Range: 0 - 65535

i1-start
Iterator {i1} start value.
Default: 1 Range: 0 - 4294967295

i1-step
Iterator {i1} step per session.
Default: 1 Range: 0 - 4294967295

i2-start
Iterator {i2} start value.
Default: 1 Range: 0 - 4294967295

i2-step
Iterator {i2} step per session.
Default: 1 Range: 0 - 4294967295

monkey
Enable monkey testing.
Default: 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",
            "session-group-id": 1,
            "username": "pta@rtbrick.com",
            "outer-vlan-min": 1000,
            "outer-vlan-max": 1999,
            "inner-vlan-min": 7,
            "inner-vlan-max": 7
        },
        {
            "interface": "eth1",
            "type": "pppoe",
            "session-group-id": 2,
            "username": "l2tp@rtbrick.com",
            "outer-vlan-min": 2000,
            "outer-vlan-max": 2999,
            "inner-vlan-min": 7,
            "inner-vlan-max": 7
        },
        {
            "interface": "eth3",
            "type": "pppoe",
            "session-group-id": 1,
            "username": "test@rtbrick.com",
            "outer-vlan-min": 128,
            "outer-vlan-max": 4000,
            "inner-vlan-min": 7,
            "inner-vlan-max": 7
        },
        {
            "interface": "eth4",
            "type": "ipoe",
            "session-group-id": 3,
            "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, password, agent-remote-id, agent-circuit-id, and cfm-ma-name support variable substitution. The variable {session-global} will be replaced with the actual session-id starting from 1 and incremented for every new session. The variable {session} is incremented per-interface section. The variables {outer-vlan} and {inner-vlan} will be replaced with the corresponding VLAN identifier or 0 if not defined. The two variables {i1} and {i2} are configurable per-interface sections with user-defined start values and steps.

The BNG Blaster supports the VLAN mode 1:1 (default) and N:1. The first one assigns a dedicated VLAN per subscriber. The VLAN mode N:1 assigns one VLAN to N subscribers and therefore only one VLAN combination is supported per access interface section using this mode.

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

One or more access interface blocks can be grouped using the session-group-id, which allows applying some commands like session-start, session-stop or session-restart to all sessions belonging to the same group. The example below shows how to assign all even VLAN identifiers to session group 1 and all odd VLAN identifiers to session group 2.

{
    "access": [
        {
            "interface": "eth1",
            "type": "pppoe",
            "session-group-id": 1,
            "username": "even@rtbrick.com",
            "outer-vlan-min": 1000,
            "outer-vlan-max": 1998,
            "outer-vlan-step": 2,
            "inner-vlan": 7
        },
        {
            "interface": "eth1",
            "type": "pppoe",
            "session-group-id": 2,
            "username": "odd@rtbrick.com",
            "outer-vlan-min": 1001,
            "outer-vlan-max": 1999,
            "outer-vlan-step": 2,
            "inner-vlan": 7
        },
    ]
}

The BNG Blaster supports access and network interface functions on the same interface link if both are tagged with disjoint VLAN ranges.

A10NSP Interfaces

The A10NSP interface function is required for L2BSA tests and emulates a layer two provider interface. The term A10 refers to the end-to-end ADSL network reference model from TR-025.

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

Attribute

Description

interface
Parent interface/link name (e.g. eth0, …).

qinq
Set outer VLAN ethertype to QinQ (0x88a8).
Default: false

mac
Optional set gateway interface address manually.
Default: parent interface/link MAC address

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

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

Note

The A10NSP interface function can’t reside on the same link with with network or access interface functions!

I/O Modes

The BNG Blaster supports many configurable I/O modes listed with bngblaster -v. In the default mode packet_mmap_raw, all packets are received in a Packet MMAP ring buffer and sent through RAW packet sockets.

$ bngblaster -v
Version: 0.8.1
Compiler: GNU (7.5.0)
IO Modes: packet_mmap_raw (default), packet_mmap, raw

Packet MMAP

Packet MMAP is a so-called PACKET_RX_RING/PACKET_TX_RING abstraction where a user-space program gets a fast lane into reading and writing to kernel interfaces using a shared ring buffer. The shared ring buffer is a memory-mapped window shared between the kernel and the user space. This low overhead abstraction allows us to transmit and receive traffic without doing expensive system calls. Sending and transmitting traffic via Packet MMAP is as easy as copying a packet into a buffer and setting a flag.

Using I/O mode packet_mmap_raw or packet_mmap limits the maximum stream packet length to 3936 bytes on most systems. The actual limit is dynamically calcualted based on pagesize (typically 4096) minus overhead.

RAW

RAW Packet Sockets. are used to receive or send raw packets at the device driver (OSI layer 2) level.

The I/O mode raw allows steam packet lengths of up to 9000 bytes (layer 3).

DPDK

DPDK support should be considered as experimental. This I/O mode is detailed explained in the DPDK section of the performance guide.