Avaya Voice Over IP Phone - Issues with connecting?

I am trying to set up my Avaya VOIP phone (model 5610SW IP), but I can't get past the exchanging keys stage. The phone keeps reading with the following error: IP IKE Phase 1 No Response; error code 3997700:0. I've been over this issue with my job's tech support department since they are the ones who provided the phones and set them up in our office without any issues. Would this be a problem with my internet provider? I have Hotwire and I'm thinking that since they have a monopoly over our apartment complex, they may have placed certain restrictions on how the residents use the internet connection. I was also thinking it might be my router? I have a Motorola SBG900 Wireless Surfboard Gateway. Has anyone run into an issue like this in the past and resolved it?