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 an 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 E-LAN based T-UNI is supported. All T-UNI I-SID end points for a given I-SID become members of the same shared E-LAN 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 ISID. 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 ISID mapped to a T-UNI service must not be mapped to any other service, such as L2 VSN and L3 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 ISID , LLDP PDUs are transparently bridged across the T-UNI port or MLT.
SLPP
VRRP
OSPF
RIP
BGP
ISIS
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.