Abstract: Techniques are provided for handling failures of DNS (domain name system) servers to respond to DNS queries. A DNS resolver is configured to resolve domain names, and includes a time-to-live (TTL)-based cache, a negative cache, and a long term store cache. The TTL-based cache is configured to temporarily store domain names with resolved IP addresses. The negative cache is configured to store negative entries that include information indicating domain names that were failed to be resolved. The long term store cache is configured to store domain names with resolved IP address for an indefinite time period. The caches are accessed in a manner that enables fewer DNS query retries to be performed when a DNS server is non-responsive, to reduce delays and network traffic. Furthermore, the DNS resolver may reduce a number of DNS queries performed the longer the DNS server stays non-responsive.

Abstract: A system and method is described that allows a system operator to remotely detect and diagnose a voice-enabled cable modem that has entered a chattering line state so that appropriate steps may be taken to avoid or rectify any of the problems that may result from this condition. Logic within the voice-enabled cable modem monitors for pulse dialing activity and/or excessive hook state and/or flash events that may be attributed to a faulty telephone and/or telephone line connected to the voice-enabled cable modem. Responsive to detecting such conditions, the logic within the voice-enabled cable modem reports a fault condition to an external management system via a cable data network.

Abstract: Techniques are provided for handling failures of DNS (domain name system) servers to respond to DNS queries. A DNS resolver is configured to resolve domain names, and includes a time-to-live (TTL)-based cache, a negative cache, and a long term store cache. The TTL-based cache is configured to temporarily store domain names with resolved IP addresses. The negative cache is configured to store negative entries that include information indicating domain names that were failed to be resolved. The long term store cache is configured to store domain names with resolved IP address for an indefinite time period. The caches are accessed in a manner that enables fewer DNS query retries to be performed when a DNS server is non-responsive, to reduce delays and network traffic. Furthermore, the DNS resolver may reduce a number of DNS queries performed the longer the DNS server stays non-responsive.

Abstract: A system and method is described that allows a system operator to remotely detect and diagnose a voice-enabled cable modem that has entered a chattering line state so that appropriate steps may be taken to avoid or rectify any of the problems that may result from this condition. Logic within the voice-enabled cable modem monitors for pulse dialing activity and/or excessive hook state and/or flash events that may be attributed to a faulty telephone and/or telephone line connected to the voice-enabled cable modem. Responsive to detecting such conditions, the logic within the voice-enabled cable modem reports a fault condition to an external management system via a cable data network.