Multi-service gateway testing with CDRouter

Multi-service gateways are typically configured with two or more independent, logical WAN connections, or channels, for different services, such as voice, video, and data. These service channels are then aggregated onto a single physical WAN connection through the use of VLANs. This allows operators to easily manage, route, and prioritize traffic from a large number of subscribers.

CDRouter can easily test gateways that are configured for multiple services, ensuring that your products can deliver them effectively to subscribers and businesses.

Basic Test Setup

Each service channel supported by the multi-service gateway is independent and has its own IP stack, WAN connectivity options, and configuration. Internal routing mechanisms within the multi-service gateway determine how to route traffic between the various services that are provisioned. In addition, the primary service channel may optionally be dual-stack supporting both IPv4 and IPv6 connectivity on the WAN.

The basic test setup for a multi-service gateway is very similar to that of an Ethernet to Ethernet router or a DSL router. There is a single physical WAN connection which is typically Ethernet or DSL based. The primary difference is that there are multiple logical connections each running on a different VLAN over the single physical WAN interface.

A basic CDRouter test setup for an Ethernet to Ethernet multi-service gateway is shown below (the device under test, or DUT, is the Ethernet to Ethernet multi-service gateway).

Likewise, the test setup for a DSL based multi-service gateway is shown below. The only the difference is the inclusion of an IP DSLAM which terminates the DUT’s WAN DSL connection and routes all service channels from the DUT upstream via Ethernet which is connected directly to CDRouter.

In both setups, the LAN side of the multi-service gateway requires no special configuration and behaves like any other gateway. The multi-service aspect is independent of the LAN configuration, and relies on internal routing mechanisms to properly route traffic between the LAN and the applicable service channel, and vice versa.

CDRouter Example Configuration

For multi-service gateways CDRouter treats each service channel as a separate WAN connection. This requires CDRouter Multiport, which allows up to 64 unique WAN interfaces to be defined and connected to a single CDRouter system.

Assume that the DUT is an Ethernet to Ethernet multi-service gateway with three service channels, referred to as “voice”, “video”, and “data” as shown in test setup 1 above. Each service channel is configured with a unique VLAN ID, and only the “data” service channel is dual-stack, as summarized in the following table:

Service Channel VLAN ID VLAN Priority IPv4 WAN Mode IPv6 WAN Mode WAN Interface
Data 100 0 PPPoE PPPoE with DHCPv6 PD Primary (wan)
Voice 200 0 DHCP None Secondary (wan2)
Video 300 0 DHCP None Secondary (wan3)

The CDRouter configuration for this basic setup requires the definition of three WAN interfaces. The primary WAN interface is associated with the “data” service channel, which is a dual-stack connection using PPPoE for IPv4 connectivity and PPPoE plus DHCPv6 with prefix delegation for IPv6 connectivity. The “data” service channel would have the following WAN side CDRouter configuration (note that this is only a partial configuration):

# -- Primary WAN interface config for the "data" service channel
testvar wanInterface eth2
testvar wanIspIp              16.0.0.1
testvar wanIspAssignIp        16.0.0.2
testvar wanNatIp              16.0.0.2
testvar wanIspNextIp          16.0.0.3
testvar wanIspMask            255.255.255.0
testvar wanVlanId             100
testvar wanVlanPriority       0
testvar wanDomainName         qacafe.com
testvar wanDnsServer          1.1.1.1
testvar wanBackupDnsServer    1.1.1.2
testvar wanMode               PPPoE

# -- PPPoE configuration
testvar pppoeUser             qacafe
testvar pppoePassword         qacafe123
testvar pppoeAcName           qacafe-ac
testvar pppoeServiceName      any

# -- general PPP configuration
testvar pppAuthType           PAP

# -- WAN interface type
testvar wanAlwaysOn           yes

# - IPv6 setup
testvar supportsIPv6		yes
testvar ipv6WanMode		PPPoE
testvar ipv6PPPoEAddressMode    DHCP
testvar ipv6WanIspIp          3001::1
testvar ipv6WanIspAssignIp    3001::2
testvar ipv6WanIspNextIp      3001::3
testvar ipv6WanIspPrefixLen   64
testvar dhcpv6WanEnablePD     yes
testvar dhcpv6WanAssignPrefix 3001:dddd::
testvar dhcpv6WanAssignNextPrefix 3001:ddde::
testvar dhcpv6WanAssignPrefixLen 48
testvar dhcpv6PDLatency       30

Likewise, the “voice” and “video” service channels must be configured as an additional WAN interfaces on the same physical interface within CDRouter. Additional WAN interfaces are configured as testvar_groups within CDRouter:

# -- CDRouter config for "voice" service channel

testvar_group wan2 {

   # -- Ethernet WAN
   testvar wanInterface          eth2

   # -- WAN configuration
   testvar wanIspIp              17.0.0.1
   testvar wanIspAssignIp        17.0.0.2
   testvar wanNatIp              17.0.0.2
   testvar wanIspNextIp          17.0.0.3
   testvar wanIspMask            255.255.255.0
   testvar wanVlanId             200
   testvar wanVlanPriority       0
   testvar wanDomainName         qacafe.com
   testvar wanDnsServer          2.1.1.1
   testvar wanBackupDnsServer    2.1.1.2
   testvar wanMode               DHCP

   # -- DHCP configuration
   testvar dhcpLeaseTime         300
   # testvar dhcpServerBroadcast yes

   # -- WAN interface type
   testvar wanAlwaysOn           yes
}
# -- CDRouter config for "video" service channel

testvar_group wan3 {

   # -- Ethernet WAN
   testvar wanInterface          eth2

   # -- WAN configuration
   testvar wanIspIp              18.0.0.1
   testvar wanIspAssignIp        18.0.0.2
   testvar wanNatIp              18.0.0.2
   testvar wanIspNextIp          18.0.0.3
   testvar wanIspMask            255.255.255.0
   testvar wanVlanId             300
   testvar wanVlanPriority       0
   testvar wanDomainName         qacafe.com
   testvar wanDnsServer          3.1.1.1
   testvar wanBackupDnsServer    3.1.1.2
   testvar wanMode               DHCP

   # -- DHCP configuration
   testvar dhcpLeaseTime         300
   # testvar dhcpServerBroadcast yes

   # -- WAN interface type
   testvar wanAlwaysOn           yes
}

Management via TR-069

Many multi-service gateways also support device management via TR-069. Management traffic may be confined to its own separate service channel, or it can share an existing service channel, as shown in the test setup below:

CDRouter TR-069 Configuration

CDRouter supports the testing of TR-069 in a multi-service gateway environment regardless of which service channel the management traffic is routed to. For the test setup above, TR-069 traffic is routed to the “data” service channel on VLAN 100. Using the configuration examples above, VLAN 100 is configured as the primary WAN interface within CDRouter. To configure CDRouter for TR-069 on this service channel, the testvar acsInterface (new for CDRouter 7.3) must be included in the CDRouter configuration file.

The acsInterface testvar specifies the network interface CDRouter will attach the ACS to. CDRouter’s default, primary WAN interface is simply referred to as “wan”. Additional, secondary WAN interfaces are typically referred to as “wan2”, “wan3”, etc. To configure CDRouter to test TR-069 on the “data” service channel in the example described above, the testvar acsInterface must be set to a value of “wan”:

testvar acsInterface wan

CDRouter will ignore all TR-069 traffic that is received on the “voice” and “video” service channels. If TR-069 is instead routed to the “voice” service channel, the testvar acsInterface must be set to “wan2”.

Multicast Traffic

CDRouter includes support for testing multicast traffic on secondary WAN interfaces. The multicastInterface testvar specifies the network interface CDRouter will use for multicast testing. To configure CDRouter to test multicast on the service channel attached to “wan2”, for example, the testvar multicastInterface must be set to a value of “wan2”:

testvar multicastInterface wan2

CDRouter will ignore all multicast traffic that is received on any WAN interface or service channel other than “wan2”. Note that this feature applies to multicast over both IPv4 and IPv6.

SIP Traffic

CDRouter can assign a multi-service WAN interface to be dedicated to SIP test traffic. When assigned, CDRouter will ignore any SIP traffic received on any other interface. This can be set with the sipInterface testvar, for example:

  testvar sipInterface wan2

This feature also works with both IPv4 and IPv6 SIP traffic.