Ethernet Traffic On A Ring - Alcatel-Lucent 9500 MXC User Manual

Ethernet Traffic on a Ring

Radio Environment
3DB 23063 ADAA - Rev 004 July 2007
9500 MXC platforms offer multiple solutions for protection of Ethernet traffic on
a ring:
• Protection can be provide in a radio environment where Nx2 Mbps or Nx1.5
Mbps circuits used to transport the Ethernet data are protected by the 9500
MXC Super-PDH ring-wrapping mechanism. Refer to Radio Environment on
page 3-87.
• Protection can be provided in an Ethernet environment using the Spanning Tree
Protocol (STP) or Rapid Spanning Tree Protocol (RSTP) on a L2 switch
installed at Node sites. Refer to Ethernet Environment on page 3-88.
A circular connection or loop occurs when there is more than one Ethernet path
to reach a destination. A spanning tree capability is required to resolve such
loops.
The transport solutions are provided by:
• 9500 MXC Node with the DAC ES for Fast Ethernet. Ring protection options
include radio-environment, and Ethernet-environment. With
Ethernet-environment an external RSTP switch is normally installed at each
site.
• 9500 MXC Node with DAC GE for Gig-Ethernet. Ring protection is supported
in an Ethernet-environment only, with the DAC GE providing an enhanced
RSTP function; RWPR
switch is not required.
• 9500 MXC IDU ES for Fast Ethernet. Ring protection is supported in an
Ethernet environment only, and an external RSTP switch is required at each
site. Refer to IDU ES Link on page 2-10.
Radio environment ring protection of an Ethernet channel is provided by creating
a linear (daisy-chained) Ethernet network on the ring without closing the final
Ethernet channel connections. The individual 2 Mbps or 1.5 Mbps circuits used
to support a DAC ES Ethernet channel on the ring operate in the normal
any-to-any circuit mode, to provide ring wrapping in the event of a ring break. In
this way, the protection advantages of a ring are provided without compromising
the Ethernet environment; no Ethernet loops are created so no external spanning
tree management is needed. Refer to the example in Figure 3-54 on page 3-88.
TM
(Resilient Wireless Packet Ring). An external RSTP
9500 MXC User Manual
Vol. II-3-87