Can anyone please share their experience with Cisco voip for Sip line.
Need to provide the Cisco Voip solution for 3 location
SIP Line from service provider terminated at Main office consisting of 20 DID/20 DOD with 400 extensions
This is a design question which requires lot of information to be gathered and collaboration experience. From my experience, I can suggest couple of points:
1. What kind of buisness is running and how phone dependent it is? This is important to define the SLA which will be a base line for aspects of design
2. You need to think about WAN Topology and bandwidth such full-mesh MPLS, DMVPN, or combo
3. Think about Grade of Service and whether to use Erlang B/Erlang C (for contact center enviroment) for your concurrent call calculations
4. Codec to be used for intra-call and inter-call. This is important for bandwidth calculation
5. QoS for LAN and WAN and which model to use with how many CoS
6. Deployment Model (centralized or Distributed)
7. Redundancy level (How many Sub, Local Failover or Remote Failover, SRST)
8. Router Platform to use and Amount of DSPs (Cisco Online DSP Calculator can help)
9. Which signaling protocol to use in case of multi-cluster
10. Dialplan and Numbering. Advanced Call Routing such as ILS/GDR, TEHO, etc
11. Is video calling an option
12. What endpoints are required
13. Other options such as voice mail and IM
14. CUBE Design since you are connecting to ITSP using SIP (Number of concurrent calls, HA, etc)
B6KS can have max of 150 users. Therefore main office can't use it. Also, I don't recommended it for site 1 (128 is very close to 150 and you need a space for upgrade).
If you want to go for centralized deployment you can go for B6KM which can have up to 1000 users which is more than double of you total count. Also, B6KM can support more options as such UCCX users, CUC, etc
So if I go for centralized at main site, then for site 1 & 2, what would I require in addition to layer 3 switches 3850 for routing and poe. Will the main site CBe 6000M be sufficient?
Also since the ITSP is terminating SIP trunk at main office. Do I require anything additional to be added like cube?
Will the main site CBe 6000M be sufficient?
Yes but you need to consider HA options such as SRST license on local routers.
Do I require anything additional to be added like cube?
Yes you need a CUBE to integrate with telco. Technically, you can connect CUCM directly to telco but this isn't not a right design at all.