# 判斷長的時間間隔Determining the Interval

• 小長的時間間隔降低延遲，但會增加的寬形區域 (wan) 傳輸量。A small interval decreases latency but increases the amount of wide area network (WAN) traffic.

• 若要隨時取得最新的網域 directory 磁碟分割，低延遲建議。To keep domain directory partitions up to date, low latency is preferred.

• 您網路上建立的所有網站的表格，以下的範例所示：Create a table of all the sites on your network, as shown in the following example:

網站Sites 西雅圖Seattle 波士頓Boston 洛杉磯Los Angeles 紐約New York 華盛頓特區Washington, D.C.
西雅圖Seattle 0.250.25
波士頓Boston 0.250.25
洛杉磯Los Angeles 0.250.25
紐約New York 0.250.25
華盛頓特區Washington, D.C. 0.250.25

在網站中的壞延遲估計為 15 分鐘的時間。A worst-case latency within a site is estimated to be 15 minutes.

• 從複寫排程判斷可連接兩個中樞網站的任何網站連結最多複寫延遲。From the replication schedule, determine the maximum replication latency that is possible on any site link that connects two hub sites.

例如，如果複寫發生西雅圖之間紐約每個三個小時的時間，最多複寫之間這些網站的延遲是 3 個小時。For example, if replication occurs between Seattle and New York every three hours, the maximum delay for replication between these sites is three hours. 如果紐約之間西雅圖複寫延遲率最高所有中樞網站之間排程的延遲，最大延遲是 3 個小時。If the replication delay between New York and Seattle is the longest scheduled delay among all hub sites, the maximum latency between all hubs is three hours.

• 每個中樞網站，建立的最大的延遲中樞網站和任何其衛星網站。For each hub site, create a table of the maximum latencies between the hub site and any of its satellite sites.

例如，複寫紐約之間華盛頓特區每個 4 小時發生，這是紐約和任何其衛星網站之間的長複寫延遲紐約和其衛星之間的最大延遲四小時的時間。For example, if replication occurs between New York and Washington, D.C., every four hours and this is the longest replication delay between New York and any of its satellite sites, the maximum latency between New York and its satellites is four hours.

• 將這些最大的延遲以判斷整個網路的最大的延遲。Combine these maximum latencies to determine the maximum latency for the entire network.

例如，如果在洛杉磯其衛星網站西雅圖之間的最大延遲一天，這組連結最多複寫延遲 (華盛頓特區-紐約-西雅圖-洛杉磯) 是 31 小時，也就是 4 (華盛頓特區-紐約) + 3（紐約西雅圖）+ 24 (西雅圖-洛杉磯)，如下表所示。For example, if the maximum latency between Seattle and its satellite site in Los Angeles is one day, the maximum replication latency for this set of links (Washington, D.C.-New York-Seattle-Los Angeles) is 31 hours, that is, 4 (Washington, D.C.-New York) + 3 (New York-Seattle) + 24 (Seattle-Los Angeles), as shown in the following table.

網站Sites 西雅圖Seattle 波士頓Boston 洛杉磯Los Angeles 紐約New York 華盛頓特區Washington, D.C.
西雅圖Seattle 0.250.25 4+34+3 24.0024.00 3.003.00 4+34+3
波士頓Boston 0.250.25 4+3+244+3+24 4.004.00 4.004.00
洛杉磯Los Angeles 0.250.25 24 + 324 + 3 24+3+424+3+4
紐約New York 0.250.25 4.004.00
華盛頓特區Washington, D.C. 0.250.25