We have a small lab for testing consisting of a single hub site and two branch sites. There are two MPLS clouds (MPLS1 and MPLS2) and all three sites are connected to both transports. We are running a voice stream at 87K (dscp ef), a TCP stream at 500K (dscp af21), and a set of 10 streams to fill any available bandwidth (dscp 0). With path preference configured the Voice (ef) and Fixed bandwidth TCP stream (af21) are on MPLS1 and the dscp 0 traffic is on MPLS2 because of load-sharing.
When we introduce some packet loss onto the MPLS1 network the voice traffic is not moved to MPLS2 because PfR has marked MPLS2 as out of bandwidth even though the QoS policy would allow Voice to be prioritised. Is there any way to change this behavior?
000557: Nov 3 11:50:05.116 GMT: %DOMAIN-2-IME: Immitigable event occured. IME-ID=125: Details: Instance=0: VRF=default: Source Site ID=10.129.70.11: Destination Site ID=10.129.70.10: Reason=No Alternate Exit: TCA-ID=439: Policy Violated=VOICE: Current Exit=[CHAN-ID=44, BR-IP=10.129.70.11, DSCP=ef[46], Interface=Tunnel1, Path=MPLS1[label=0:1 | 0:0 [0x10000]]]: Out Of BW Alt Exits=1: Out Of Policy Alt Exits=0
IWAN-SITE1-R1#sh domain IWAN master traffic-classes dscp ef detail
Dst-Site-Prefix: 10.129.64.0/28 DSCP: ef [46] Traffic class id:16
Clock Time: 11:52:19 (GMT) 11/03/2017
TC Learned: 01:26:48 ago
Present State: CONTROLLED
Current Performance Status: Out-of-policy (Packet Loss Threshold percent: 1.0 vs Actual: 1.92)
Current Service Provider: MPLS1 since 01:25:46
Previous Service Provider: Unknown
BW Used: 80 Kbps
Present WAN interface: Tunnel1 in Border 10.129.70.11
Present Channel (primary): 44 MPLS1 pfr-label:0:1 | 0:0 [0x10000]
Backup Channel: none
Destination Site ID bitmap: 1
Destination Site ID: 10.129.70.10 (Active)
Class-Sequence in use: 10
Class Name: VOICE using policy voice
BW Updated: 00:00:18 ago
Method for choosing channel: Random
Route Change History:
Date and Time Previous Exit Current Exit Reason
1: 10:26:33 (GMT) 11/03/17 None(0:0|0:0)/0.0.0.0/None (Ch:0) MPLS1(0:1|0:0)/10.129.70.11/Tu1 (Ch:44) Uncontrolled to Controlled Transition
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Policy Decision Point Matrix:
Test Status Legend: U - Usable, R - Reachable, L - TCA Loss, D - TCA Delay, J - TCA Jitter, B - 95% Bandwidth
Codes: P - Passed, F - Failed,
* - Present Channel, + - Backup Channel
Exit Path-Pref NH U R L D J B
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* MPLS1(0:1|0:0)/10.129.70.11/Tu1 (Ch:44) Primary Act P P F - - -
MPLS2(0:2|0:0)/10.129.70.12/Tu2 (Ch:45) Fallback Act P P P P P F
Total Traffic Classes: 1 Site: 1 Internet: 0