This excerpt taken from the VRSN 10-K filed Jul 12, 2007.
7. Performance Specifications
For purposes of this Section 7, DNS Name Server means the service complying with RFC 1034 made available on TCP/UDP port 53 on Registry Operators selected servers; Round-trip means the amount of time that it takes for a remote nameserver to respond to queries; Core Internet Service Failure means extraordinary and identifiable events beyond the control of Registry Operator affecting the Internet services to be measured pursuant to this section, including but not limited, to congestion collapse, partitioning, power grid failures, and routing failures; DNS Name Server unavailability shall mean less than four (4) sites on the Registry Operators constellation are returning answers to queries with less than 2% packet loss averaged over a Monthly Timeframe; and Monthly Timeframe means each single calendar month beginning and ending at 0000 Coordinated Universal Time (UTC). The requirements in this Section 7 set forth below are not matters subject to SLA Credits under the Service Level Agreement set forth on Appendix 10 or obligations upon which a breach by Registry Operator of the Registry Agreement may be asserted.
A. Cross-Network Name Server Performance Requirements. The committed performance specification for cross-network name server performance is a measured Round-trip of under 300 milliseconds and measured packet loss of under 10% over the course of a Monthly Timeframe. Cross-network name server performance measurements may be conducted by ICANN, pursuant to the terms of confidentiality agreements executed both by ICANN and its employee or consultant conducting the testing, in the following manner:
1. The measurements may be conducted by sending strings of DNS request packets from each of four measuring locations to each of the .com DNS Name Servers and observing the responses from the .com DNS Name Servers. (These strings of requests and responses are referred to as a CNNP Test.) The measuring locations will be four root name server locations on the US East Coast, US West Coast, Asia, and Europe.
2. Each string of request packets will consist of 100 UDP packets at 10 second intervals requesting nameserver records for arbitrarily selected .com second-level domains, preselected to ensure that the names exist in the Registry TLD and are resolvable. The packet loss (i.e. the percentage of response packets not received) and the average Round-trip time for response packets received may be noted.
3. To meet the packet loss and Round-trip requirements for a particular CNNP Test, all three of the following must be true:
(a) The Round-trip and packet loss from each measurement location to at least one .com name server must not exceed the required values;
(b) The packet loss to each of the .com name servers from at least one of the measurement locations must not exceed the required value; and
(c) Any failing CNNP Test result obtained during an identified Core Internet Service Failure shall not be considered.
4. To ensure a properly diverse testing sample, ICANN will conduct the CNNP Tests at varying times (i.e. at different times of the day, as well as on different days of the week). Registry Operator may only be deemed to have persistently failed to meet the cross-network name server performance requirement only if the .com DNS Name Servers fail the CNNP Tests (see Section 7.3 above) with no less than three consecutive failed CNNP Tests.
5. In the event of persistent failure ( defined as failure of three consecutive tests) of the CNNP Tests, ICANN will give Registry Operator written notice of the failures (with backup data) and Registry Operator will have sixty days to cure the failure.
6. Sixty days prior to the commencement of testing under this provision, ICANN will provide Registry Operator with the opportunity to evaluate the testing tools, root name server locations and procedures to be used by ICANN. In the event that Registry Operator does not approve of such tools and procedures, ICANN will work directly with Registry Operator to make necessary modifications.
7. ICANN will provide written notification to Registry Operator of the results of any testing within 5 days of completion of testing, including the method used for testing, administrator used to conduct the test and the location of testing. Within 30 days of receipt of notice the testing results, Registry Operator may request that the test be re-administered in the presence of a Registry Operator employee. This second test must be administered within 30 days of Registry Operators request.
B. Service AvailabilityDNS Name Server = 100% per Monthly Timeframe. Service Availability as it applies to the DNS Name Server refers to the ability of the DNS Name Server to resolve a DNS query from an Internet user. DNS Name Server unavailability will be logged with the Registry Operator as Unplanned Outage Minutes. Registry Operator will log DNS Name Server unavailability when such unavailability is detected by VeriSign monitoring tools. Any DNS Name Server unavailability occurring during an identified Core Internet Service Failure shall not be considered.