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New Member

QoS on MC3810 with a CCS cross connect

We have 2 MC3810s connected together via a T1 lease line using frame relay encapsulation. Each MC3810 has a DVM connecting a PBX. Both MC3810s are configured with a cross connect between the MFT and the DVM.

We are experiencing voice quality issues, and need QoS. We are unsure of our options. If possible we would like to keep the current config, but if needed it can be redesigned.

Our current config:

controller T1 0

framing esf

clock source internal

linecode b8zs

channel-group 4 timeslots 1-23 speed 64

tdm-group 1 timeslots 24


controller T1 1

framing esf

linecode b8zs

mode ccs cross-connect

tdm-group 2 timeslots 24

voice-group 3 timeslots 13-23 type ext-sig-master


interface Serial0:4.1 point-to-point

bandwidth 768

ip address x.x.x.x x.x.x.x

ip directed-broadcast

no ip route-cache

frame-relay interface-dlci 100

class vofr_cisco

vofr cisco


map-class frame-relay vofr_cisco

frame-relay voice bandwidth 768000

frame-relay fragment 1600

no frame-relay adaptive-shaping

frame-relay cir 1544000

frame-relay bc 7680

frame-relay mincir 1544000

frame-relay fair-queue


voice-port 1/13-1/23---These voice ports are all the same

echo-cancel coverage 16

timeouts call-disconnect 0

connection trunk 113

codec g711ulaw


dial-peer voice 100 vofr

codec g711ulaw

fax-rate 9600 bytes 20

no vad

destination-pattern 1..

session target Serial0:4 100

Thanks in advance for any suggestions.

New Member

Re: QoS on MC3810 with a CCS cross connect

You will want to read through the following document on QoS:

Since you are using frame relay, the VoIP over Frame Relay with QoS page is great as it covers Fragmentation, Traffic Shaping, and LLQ / IP RTP Priority.