[Serusers] SER+Vocal Integration is failing

Hi, We are trying to call from SER to Vocal , but call is failing saying 403 forbidden. We are using kphone as user agent . UA1 is registered with SER . UA2 is registered with vocal. When we call to UA2 from UA1 , call is failing saying 403 forbidden. But if we call UA1 from UA2 then it is working properly Has anybody faced this type of problem ? Does vocal requires some config changes ? Any pointers on this will be helpful Regards, Rajesh The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com