I am using cucm 8.6(2) with IP phones,3750 POE switch,3800 Router, core switch, checkpoint firewall involved in the internal LAN network. And Qos is apllied on WAN router for Voice(DSCP EF) ,signalling packets(DSCP AF31).And we are having 3 clusters with indivdual SUB and PUB cucm.
Recently i had felt a call disruptions(no Voice heared at both sides but call got connected, no ringback and dialtone was heared).But no phones got unregistered. During that time i tried to ping my other clusters WAN Routers i experienced some latency and packet drops. I dont know my troubleshooting method is right but i had a assumption that it can be a WAN connectivity issue.
Now my question is,
1. I kept trust boundary at Wan Router only, since i didnt get ringback tone itself intra cluster signalling with local CUCM itself not proper right?.
2. And first troubleshooting i did was pinging other Wan Routers, by this step i cant able to say that voice packet got dropped, since Ping is ICMP packet(belongs to class default) and VOIP packet and signalling packet is class 5 & 3 in WAN. So how can i prove that voice packet is dropped in WAN?.
3. Is extended ping is needed from one WAN router to other WAN router?If it needed i can have option for TOS value only whether it will be helpful, since my markings are in DSCP ?.
Please help me out to solve this issue.