Use a Transparent Port User-Network-Interface (Transparent Port UNI or T-UNI) to map an entire port or an MLT to an I-SID. CMAC learning is done against the I-SID. T-UNI configures a transparent port where all traffic is MAC switched on an internal virtual port using the assigned I-SID. No VLAN is involved in this process. Devices switch tagged and untagged traffic in the assigned I-SID regardless of the VLAN ID. The T-UNI port or MLT can be either static or LACP and is not a member of any VLAN or Spanning Tree Group (STG). The T-UNI port or MLT is always in the forwarding state.
You can map multiple ports to a T-UNI I-SID. Multiple ports on the same switch and on other BEBs can use the common I-SID to switch traffic.
T-UNI is a point to point service and all traffic that ingress the UNI egress from the remote UNI end-point
For information about QoS re-marking, see QoS re-marking on a Transparent Port UNI.
T-UNI is transparent because the MAC learning occurs within the I-SID, and packets that ingress from any CVLAN are processed in an identical manner. Devices switch tagged and untagged traffic in the assigned I-SID. Devices switch control protocols, such as BPDU, LACP, LLDP, and others, in the assigned I-SID, rather than forwarding to the CP.
The service classification of packets that are received on a T-UNI port, is independent of the VLAN ID values present in those packets. All data packets received on a T-UNI port are classified into the same service. When data packets enter and exit the T-UNI service, no VLAN tag modifications are performed on the data packets.
When a packet ingresses a port or MLT associated with a T-UNI I-SID, the system performs MAC lookup based on the I-SID. A packet that ingresses a T-UNI port on a BEB can transfer through the SPB network, or can egress out another T-UNI port configured to the same I-SID.
When a packet ingresses a network-to-network interface (NNI) port, before egressing a T-UNI port, the system performs a MAC Destination Address (DA) lookup based on the I-SID. If the DA lookup fails, the packet floods to all T-UNI ports.
Only ELAN based T-UNI is supported. All T-UNI I-SID end points for a given I-SID become members of the same shared ELAN service. If an E-LINE type of service is required, provision T-UNI at the two end points comprising the point-to-point service.
You cannot configure a T-UNI on the same I-SID as a C-VLAN.
A port or MLT associated with a T-UNI I-SID cannot be part of any VLAN and does not belong to any STG.
Ensure that you always associate a T-UNI LACP MLT with a VLAN (even if it is the default VLAN) before adding it to a T-UNI I-SID. Otherwise, traffic is not forwarded on the T-UNI LACP MLT.
No Layer 3 processing takes place on packets ingressing on a T-UNI port.
Pause frames do not switch through the T-UNI I-SID.
Multiple ports or MLTs can be associated with same T-UNI I-SID.
One port or MLT cannot be part of multiple T-UNI I-SIDs.
An I-SID mapped to a T-UNI service must not be mapped to any other service, such as Layer 2 VSN and Layer 3 VSN, on any of the remote BEBs in the SPBM network.
Any Spanning Tree Protocol implementation is disabled on the port or MLT associated with the T-UNI I-SID. The port will always be in a Forwarding state.
No additional IS-IS TLVs are added to advertise or withdraw T-UNI I-SID services. Extreme Networks makes use of the existing IS-IS TLV-144 and sub TLV-3 to carry I-SID information.
MACs are learned against the combination of the I-SID and port or MLT.
Note
MAC learning limit for T-UNI service is not supported on all hardware platforms.
Static MAC is not supported for a T-UNI port.
IP traffic and control packets are transparently bridged over T-UNI endpoints.
Untagged traffic ingressing on the T-UNI port will use COS 0. B-TAG and I-TAG priorities are derived from the best effort queue that is assigned. If the T-UNI port is set as a Layer 2 untrusted port, a best-effort queue is assigned.
The 802.1p bits of the incoming traffic are used to derive the B-TAG and I-TAG priorities for tagged traffic.
LACP, VLACP and LLDP PDUs are extracted to the CP and all other control packets are transparently bridged over the T-UNI port or MLT.
This feature handles control PDUs in the following manner:
If an LACP MLT is associated with a T-UNI I-SID, LACP PDUs are extracted to CP and processed locally.
If LACP is not enabled globally and LACP MLT is not associated with the T-UNI I-SID, LACP PDUs are transparently bridged across the T-UNI port or MLT.
If a VLACP enabled port is added to a T-UNI I-SID, VLACP PDUs are extracted to the CP for local processing. If a port that is not VLACP enabled is added to the T-UNI I-SID, VLACP PDUs are transparently bridged across T-UNI port.
If a LLDP enabled port is added to a T-UNI I-SID, LLDP PDUs are extracted to the CP for local processing.
If LLDP is not enabled on the port or MLT interface associated to TUNI I-SID , LLDP PDUs are transparently bridged across the T-UNI port or MLT.
SLPP
VRRP
OSPF
RIP
BGP
IS-IS
CFM
STP
SONMP
Use T-UNI when either of the following apply:
All tagged and untagged traffic on a port must be classified into the same broadcast domain.
You want to offer a transparent provider solution.
An example of an application for T-UNI is a typical Ethernet provider deployment with port-based classification and transparent forwarding.