{'fraction_non_alphanumeric': 0.026501766784452298, 'fraction_numerical': 0.007067137809187279, 'mean_word_length': 4.7272727272727275, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
NAT traversal for SIP-based presence services with symmetric dialog routing

SIP (Session Initiation Protocol) uses UDP and TCP as a transport protocol as well as SCTP, TLS. In the case of using UDP as a transport protocol, it is required to guarantee symmetric response routing for NAT or FW traversal. By the way, in the case of RFC3265-based presence services using SIP, there is some situation that requires symmetric dialog request/response routing for NAT. In this paper, we describe the way of guaranteeing symmetric SIP message routing within same IP-dialog.