[c-nsp] Looking for advice on QoS for PPPoE Sessions - dsl tails

Wed May 7 00:27:09 EDT 2014

Hi

We are looking to provide some basic QoS (prioritise voip) on egress traffic towards dsl customers.

What i'd like some direction on is how to handle different dsl line rates.

Topology
Customer connects to DSL dslam provided by local telco.
Local Telco does PPPoA to PPPoE conversion and presents each customer as a unique svid/cvid over a GiGE handover
We then terminate each connection onto cisco ASR 1001
We use freeradius + mysql in back end.

If I apply a policy via radius a attribute (Cisco-AVpair += sub-qos-policy-out=pm-egress-xdsl - configs below) where the parent policy has greater bandwidth than the dsl sync rate some voip traffic still gets lost.  A show policy-map interface viX shows packets are getting matched.

If I apply a policy that shapes close to what the dsl connection can do (policy-map pm-egress-4Mbps)  QoS works as expected.

I'm generating load by running an IPERF UDP stream towards a host connected via ADSL.  When I get packet loss from pings I consider the link "congested".

So the question I have is - is there a way to dynamically set the parent policy that does the shaping ?

I see in radius debugs there are attributes actual-data-rate up/down.  Is there a way to use this information ?

Any pointers on where to look for more information would be appreciated.

Thanks

Bryan

class-map match-any cm-high-priority-traffic ! parket DSCP is set further upstream where they enter our network
 match dscp ef
 match dscp cs3
 match dscp af41
 match dscp af42

policy-map pm-egress-xdsl
 class class-default
 shape average 50m
 service-policy pm-egress-highpriority-sp

policy-map pm-egress-4Mbps
 class class-default
 shape average 4m
 service-policy pm-egress-highpriority-sp

policy-map pm-egress-highpriority-sp
 class cm-high-priority-traffic
  priority 2560

May  7 13:57:29.912 NZST: RADIUS:  authenticator 5C AA D1 FC 91 DE FD 0C - 04 50 42 9F AE D2 7D 04
May  7 13:57:29.912 NZST: RADIUS:  Acct-Session-Id     [44]  10  "03AACA51"
May  7 13:57:29.913 NZST: RADIUS:  Vendor, Cisco       [26]  37
May  7 13:57:29.913 NZST: RADIUS:   Cisco AVpair       [1]   31  "actual-data-rate-upstream=848"
May  7 13:57:29.913 NZST: RADIUS:  Vendor, Cisco       [26]  40
May  7 13:57:29.913 NZST: RADIUS:   Cisco AVpair       [1]   34  "actual-data-rate-downstream=4270"
May  7 13:57:29.913 NZST: RADIUS:  Framed-Protocol     [7]   6   PPP                       [1]
May  7 13:57:29.913 NZST: RADIUS:  Framed-IP-Address   [8]   6   114.134.170.19
May  7 13:57:29.913 NZST: RADIUS:  User-Name           [1]   13  "someuser"
May  7 13:57:29.913 NZST: RADIUS:  Vendor, Cisco       [26]  35
May  7 13:57:29.913 NZST: RADIUS:   Cisco AVpair       [1]   29  "connect-progress=LAN Ses Up"
May  7 13:57:29.913 NZST: RADIUS:  Vendor, Cisco       [26]  31
May  7 13:57:29.913 NZST: RADIUS:   Cisco AVpair       [1]   25  "nas-tx-speed=1000000000"
May  7 13:57:29.913 NZST: RADIUS:  Vendor, Cisco       [26]  31
May  7 13:57:29.913 NZST: RADIUS:   Cisco AVpair       [1]   25  "nas-rx-speed=1000000000"
May  7 13:57:29.913 NZST: RADIUS:  Acct-Session-Time   [46]  6   186151
May  7 13:57:29.913 NZST: RADIUS:  Acct-Input-Giga-Word[52]  6   0
May  7 13:57:29.913 NZST: RADIUS:  Acct-Output-Giga-Wor[53]  6   2
May  7 13:57:29.913 NZST: RADIUS:  Acct-Input-Octets   [42]  6   3722436589
May  7 13:57:29.913 NZST: RADIUS:  Acct-Output-Octets  [43]  6   2702407559
May  7 13:57:29.913 NZST: RADIUS:  Acct-Input-Packets  [47]  6   12437102
May  7 13:57:29.913 NZST: RADIUS:  Acct-Output-Packets [48]  6   16260611
May  7 13:57:29.913 NZST: RADIUS:  Acct-Authentic      [45]  6   RADIUS                    [1]
May  7 13:57:29.913 NZST: RADIUS:  Acct-Status-Type    [40]  6   Watchdog                  [3]
May  7 13:57:29.913 NZST: RADIUS:  NAS-Port-Type       [61]  6   Virtual                   [5]
May  7 13:57:29.913 NZST: RADIUS:  NAS-Port            [5]   6   0
May  7 13:57:29.913 NZST: RADIUS:  NAS-Port-Id         [87]  34  "ether 0/0/2:174.2727 0/0/0/0/0/0"
May  7 13:57:29.913 NZST: RADIUS:  Vendor, Cisco       [26]  41
May  7 13:57:29.913 NZST: RADIUS:   Cisco AVpair       [1]   35  "client-mac-address=0090.d06a.a87e"
May  7 13:57:29.913 NZST: RADIUS:  Vendor, Cisco       [26]  55
May  7 13:57:29.913 NZST: RADIUS:   Cisco AVpair       [1]   49  "circuit-id-tag=AVD-DSLAM-05 atm 1/1/13/27:0.100"
May  7 13:57:29.913 NZST: RADIUS:  Vendor, Cisco       [26]  53
May  7 13:57:29.913 NZST: RADIUS:   Cisco AVpair       [1]   47  "remote-id-tag=104197314-AVD-DSLAM-05-1-013-27"
May  7 13:57:29.913 NZST: RADIUS:  Service-Type        [6]   6   Framed                    [2]
May  7 13:57:29.913 NZST: RADIUS:  NAS-IP-Address      [4]   6   114.134.167.7