19 20HELPFUL HINTS1. To make a selection, key the highlighted letter that corre-sponds to a menu selection.2. To execute the selection, type 3. Select g Save Changes from Main Menu after making modi-fications to any NetLink-T1™ parameter. When the changesare saved, the Model 2710RC will implement the changes andsave the new settings into non-volatile memoryThe Main Menu options are briefly described below.System Configuration options allow you to change variousaspects of the NetLink-T1™’s operation, e.g., framing, linecoding, and aggregate bandwidth.System Diagnostics/Statistics options allow you to monitorthe network performance, initiate RDL loops, local loops, andsend test patterns. Network performance parameters areupdated once a second, giving you the ability to quickly deter-mine if there is a problem.Unit Information allow you to customize the NetLink-T1™ foryour location. You can change the default header names togive each unit a unique name and password. Also, you canreset the unit to its default settings without the manual. It alsohas a Service Information screen in case you need technicalassistance from Patton.Save Changes Once you have configured the unit to your sat-isfaction, you can save the changes permanently by executingthe Save Changes command. This will update the unit’s config-uration and save all the parameters to permanent memory.Logoff For security, log off the control menu by executing theLogoff command. This will blank the screen until an [Enter]key is pressed.3.3.4 System ConfigurationThe default System Configuration menu looks like this:The System Configuration options are described below:Line Format: ESF(default)Options: ESF, D4, UNFRAMEDD4: This is an older, but widely used, line format that does not pro-vide FDL, so network interface performance cannot be moni-tored so easily. AT&T TR 62411 contains the specifications forthis format and the ESF. D4 is also known as Superframe for-mat. According to TR 62411, “The Superframe format…consistsof 12 frames of 193 bits each for a total of 2316 bits. Each 193bit frame consists of 192 bits preceded by one framing bit….theframing bit is time shared to both synchronize the terminalequipment and to identify the signaling frames.” (Sec. 4.1.1)ESF: This stands for Extended Superframe Format, a line formatdeveloped by AT&T. AT&T Technical Reference 54016 (TR54016) defines the ESF, a format which is commonly used toallow monitoring of the network interface performance overthe Facility Data Link (FDL). AT&T TR 62411 says, “theExtended Superframe Format “extends” the DS1 superframestructure from 12 to 24 frames…for a total of 4632 bits. Itredefines the 8 kb/s channel previously used exclusively forterminal and robbed bit signaling synchronization.” The ESFprovides a 4 kb/s data link, called the FDL, which allows forin-service monitoring and fast troubleshooting. Certain net-work services require the ESF.cdeaabd
