Zte FSAP 9800, Technical Manual

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Chapter 3 Services
Port Location
Port location and identification is a capability of the service gate-
way and background system to obtain the physical location of sub-
scribers. For example,
BAS is used to get the port number of a
DSL subscriber for authentication, charging, and identification.
� VBAS
VBAS protocol provides an applicable method for communica-
tion between BAS and
IP DSLAM . VBAS protocol adds a com-
munication process between BAS and IP DSLAM, which can get
the detailed subscriber information.
i. The subscriber sends an identification request packet to the
BAS.
ii. The BAS sends the VBAS request packet to the DSLAM to
query the relationship between the MAC address of the sub-
scriber host and the DSLAM physical port.
iii. After receiving the VBAS request packet, the DSLAM sends
the VBAS response packet to the BAS to return the rela-
tionship between the MAC address of the subscriber host
and the DSLAM physical port.
iv. The BAS authenticates the subscriber information locally or
remotely.
� PPPoE +
PPPoE+ is an improved protocol based on PPPoE. It modifies
PPPoE protocol messages on the DSLAM.
In the discovery phase, PPPoE+ adds subscriber information to
the BAS. The BAS maintains the relationship between the sub-
scriber physical location information and the subscriber session
ID. In the
LCP authentication phase, the subscriber physical lo-
cation information is sent with the user name and password to
the
RADIUS server for authentication.
� DHCP Option 82
In the DHCP process, the identification information on the sub-
scriber port is added to the DHCP packet.
The DHCP server inserts Option 82 to the subscriber DHCP
messages. The DHCP implements the IP address distribution
policy and other policies by identifying Option 82. The response
message of the DHCP server also has Option 82. The DHCP
strips Option 82 before sending the message to the subscriber.
�
VLAN stacking
VLAN stacking allows a service provider to distinguish multiple
subscriber VLANs, even those with the same (subscriber-as-
signed) VLAN ID, within its network.
VLAN stacking is used for port location. VLAN stacking meets
the subscriber demands of VLAN expansion and dedicated line
batch service. If VLAN stacking is applied to extend VLAN num-
ber and identify subscribers, BAS is required. If it is used to
provide dedicated line batch service, it is required that the up-
per-level network is layer-2 working mode. The service is for-
warded based on VLAN and MAC address.
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