Chapter
6 Monitoring and Diagnostics
Installation and Operation Manual
6-112
Frequently Asked Questions
ACE-3105, ACE-3205 Ver. 5.2
ACE
PW1, PW2, PW3
ETH
VP1, VP2, VP3
STM-1
3
3
2
2
1
1
PW
VP
3
3
2
2
1
1
PW
VP
ACE
ACE
PW=2
ETH
ATM
STM-1
VP=1
1
2
VP
PW
1
2
VP
PW
ATM
STM-1
VP=1
1
1
VP
PW
1
1
VP
PW
ACE
ATM
STM-1
VP=1
1
3
VP
PW
1
3
VP
PW
PW=1
ETH
PW=3
ETH
Ethernet
Network
Figure
6-69. VP Mapping to PW
Q
What kind of QoS does ACE-3105, ACE-3205 support over packet-switched
networks?
A
ACE-3105, ACE-3205 complies with 802.1p and 802.1q for L2 (VLAN), EXP
bits of MPLS and for the ToS/DSCP of the IP layer. You can assign a QoS to
each PW (configurable).
Q
How can one calculate the required Ethernet bandwidth for a PW based on
the ATM parameters?
A
Bandwidth utilization depends on the ATM connection rate, mapping methods
(VPoPSN or VCoPSN), network type (L2/MPLS or IP), VLAN existence and
number of concatenated cells. A calculator that calculates the bandwidth
based on these parameters can be obtained from
.
Q
How can end-to-end OAM be maintained over a packet-switched network?
A
ACE-3105, ACE-3205 transfers transparent End-to-End OAM over the PSN.
You can set the Intermediate mode for the OAM Descriptor, in order to
instruct ACE-3105, ACE-3205 to transparently forward the ATM OAM cells as
user data over the PSN . For more information, refer to
and
Q
How does the pseudowire connectivity check (VCCV-BFD) works?
A
BFD control messages are generated by both the local and remote ACE units,
on both directions of the pseudowire. When the local ACE unit does not
receive control messages from the remote ACE unit during a number of
transmission intervals, it declares that the PW on its receive (RX) direction is
down. The PW then enters a defect forwarding state on the local ACE unit. In
addition, the local ACE generates "control-detection-time-expired" packets
towards the remote ACE, and the remote ACE replies with "neighbor-signal-
session-down" packets. For more information, refer to
Q
What is "Misorder" in the context of packet-switched traffic?