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SIP Over Coaxial/Cable Modem #terrified

SIP Over Coaxial/Cable Modem #terrified

SIP Over Coaxial/Cable Modem #terrified

Hey all,

Question: Is SIP over coaxial/cable modem service a good idea?

Reason: The carrier in my area who we have been putting SIP over fiber without having to purchase fiber internet as well (saving the customer a ton of money) has decided they will no longer do this. They will, however, still put SIP over coaxial (with its own modem). I have been down this road with this carrier before and we have had very mixed success. We have 3 or 4 customers we have put on SIP over coax and have never heard so much as a peep other than the occasional modem reboot. However, we have also have 3 or 4 customers who have had an absolute nightmare with SIP with intermittent call quality due to latency (pings just randomly start jumping over 300ms at random points throughout the day, have seen it has high as 1300ms) in different locations throughout the city. After numerous arguments for each of these problem clients, it has always wound up being the carrier's plant issues (bad wire/bad connection/bad tap/overloaded node/etc). They all eventually got fixed, but most of them took us 6 months to a year to resolve with the local repair teams and it took calling every number we had in the book to get them to take the issue seriously and resolve it.

I really don't want a repeat of these clients, however, SIP is such a great value for our clients that it seems to be our only option. Has anyone out there had mostly positive experiences with SIP over coax and what tactics did you use to make sure you had no problems? Did you use upgraded modems? Did you use QOS routers (we have traditionally used rv042s) and if so how did you configure them? Did you use a preliminary test on the coax circuit to ensure it would withstand the latency requirements necessary for SIP (i do not believe the issue is bandwidth related as we put our voice over a separate modem and typically on a separate LAN altogether)?

I would appreciate any and all advice as I am interested in making it work if it is possible, I just have yet to have very good luck.

Thanks so much!

RE: SIP Over Coaxial/Cable Modem #terrified

I have around 180 radios on SIP connections across the country (USA). Some are on DSL, cable modem, fractional T1's, etc. They are all brought onto our network via MPLS (EarthLink) or Cisco CVO. Your mileage will vary depending on the ISP. Many of our sites are rock solid. We do have a few that require the occasional modem reboot or the ISP is flaky. The big thing to take into consideration here is that you make sure it is secure (VPN) to protect yourself from toll fraud and hackers.

Maintain HiPath 4000 V5 & V6, OpenScape Xpert V4, Xpressions, Contact Center

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