Alcatel-Lucent 9500 MPR User Manual page 131

2.8.1.6 ASAP unit
The ASAP unit is used to transport 16xE1 ATM traffic, with E1/IMA physical layer, in an MPR network.
The ASAP units are unprotected (No 1+1 EPS is available).
ATM traffic is transported within MPR network as "special" Ethernet traffic.
This "special" Ethernet traffic is managed by MPR following to RFC 4717 (IETF ATM PseudoWire Edge-
toEdgeEmulation, PWE3) with N-1 encapsulation format.
ATM PW Ethernet traffic is managed by MPR is such a way to emulate the native QoS that would be
applied by an ATM equipment; in addition to that, specific techniques, similar to those applied to
TDM2ETH traffic, are applied to have air bandwidth optimisation (ATM PW Header Compression) and
reduce Cell Error Rate degradation due to packetization.
Main Characteristics
– 16xE1 G.704 supporting ATM/IMA
– IMA protocol 1.1
– Node-timed/loop-timed E1 port synch
– ATM PWE3 encapsulation with N-to-one (N=1) encapsulation format (RFC 4717)
– Max 8 IMA group
– Max 16 E1 per IMA group
– The IMA group must be in the same ASAP card
– Ingress/Egress VPI translation
– Transport of ATM traffic can be done in VCC mode or VPC mode (all the nodes of the MPR chain
must have the same mode):
• VCC mode
– It is possible to transport max 48 VC for every IMA group. It is possible to manage VC
switching (= VCI and VPI change)
– It is possible to assign at every VC one specific QoS. Policing and shaping at ATM level
has performed VC mode only
– The VC of the same class level (CBR / UBR+ / UBR) are managed in the same radio
queue, then are available 3 different radio queues
• VPC mode
– It is possible to transport max 48 VP for every IMA group. It is possible to manage only
VP switching (=only VPI change)
– All the VC inside the VP must have same QoS (= for ex. all CBR or all UBR)
– The radio QoS (= radio tails) and QoS ATM (=policing and shaping) is managed only at
VP level.
N.B. The sum of VP + VC configured on a single ASAP card must be <128.
User Manual
Product information and planning 3DB18809AAAA Issue 1
9500 MPR Rel. 3.1
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