3Com Router User Manual

CT1/PRI Interface137
■The rules for address translation or packet filtering need to be set if the firewall 
is to be set up on the interface.
For more details, refer to the related sections of this manual.
3Bind an interface to be a pri set
Perform the following configurations in CT1/PRI interface view.
Ta b l e 140   Bind the interface to be a pri set
Timeslots on a CT1/PRI interface can be bound to be only one pri set.
When binding an interface to be a pri set, timeslot 24 is used as the D channel and...

138CHAPTER 10: CONFIGURING WAN INTERFACE
By default, the attenuation of transmission cable that the CT1/PRI interface 
matches is long 0db.
5Set the line code format
A CT1/PRI interface supports two types of line code formats: ami format and b8zs 
format.
Perform the following configurations in CT1/PRI interface view.
Ta b l e 143   Set the line code format on the CT1/PRI interface
By default, the line code format on the CT1/PRI interface is b8zs.
6Set line clock
When the CT1/PRI interface operates as...

E1-F Interface139
By default, the frame format of CT1/PRI interface is ESF.
8Enable/disable internal loopback/external loopback
The interface needs to be set to internal loopback or external loopback when 
during the test on some special functions.
Perform the following configurations in CT1/PRI interface view.
Ta b l e 146   Enable/disable the internal loopback/external loopback of the CT1/PRI
By default, the functions of internal loopback and external loopback are disabled 
on the CT1/PRI interfaces....

140CHAPTER 10: CONFIGURING WAN INTERFACE
supporting the data link layer protocols PPP, HDLC, Frame Relay, LAPB and X.25, as 
well as the network protocols IP and IPX.
When it works in framed mode, however, it is physically divided into 32 time slots 
numbered in the range of 0 to 31. In these time slots, except for time slot 0 used 
for synchronization information transmission, all the other time slots can be 
randomly bound into one channel set. E1-F interface has the rate of nx64kbps, 
owns logical...

E1-F Interface141
Perform the following configuration in E1-F interface view.
Ta b l e 150   Set interface rate after binding operation
By default, binding operation will be done on all the time slots on E1-F interface.
Time slot 0 on E1-F interface is used for synchronization information transmission. 
Therefore, in practice, only time slots 1 through 31 are bound when performing 
binding operation on all the time slots on an E1-F interface.
Unlike CE1/PRI interface, only one channel set can be bound on...

142CHAPTER 10: CONFIGURING WAN INTERFACE
Ta b l e 153   Set frame format for an E1-F interface
By default, the frame format of E1-F interface is no-CRC4.
7Enable or Disable Local Loopback/Remote Loopback
An interface should be place in local loopback or remote loopback for some 
special functionality tests.
Perform the following configuration in E1-F interface view.
Ta b l e 154   Enable/Disable local/remote loopback on an E1-F interface
By default, no E1-F interface is placed in local or remote...

T1-F Interface143
T1-F InterfaceT1-F interface is fractional T1 interface, and it is respectively simplified CT1/PRI 
interface. If there is no need to use multiple channel sets or if ISDN PRI is not 
necessary in an T1 application, it is too much to use CT1/PRI interface. At this time, 
T1-F interface is more than enough for meeting the simple T1 access 
requirements. Compared with CT1/PRI interface, T1-F interfaces is a nice low-cost 
choice for T1 access.
Compared with CT1/PRI interface, T1-F...

144CHAPTER 10: CONFIGURING WAN INTERFACE
module in slot 2. Hence, the E1-F interface will be numbered Serial 0, and the 4SA 
interfaces will be numbered Serial 1 through Serial 4, and the T1-F interfaces will 
be numbered Serial 5 and Serial 6.
2Set Interface Rate after Binding Operation
When T1-F interface works in framed mode, time slot binding on the interfaces 
can be made according to users demands.
Perform the following configuration in T1-F interface view.
Ta b l e 157   Set interface rate after...

T1-F Interface145
If T1-F interface is used as DCE, the slave clock should be selected. If it is used as 
DTE, the master clock should be selected. 
If the T1-F interfaces of two routers are directly connected, they must respectively 
work in slave and master clock modes. If the T1-F interface of the router is 
connected to an exchange, however, the exchange is working as DCE and 
provides clock, so the interface of the router should work in master clock mode. 
Perform the following configuration in T1-F...

146CHAPTER 10: CONFIGURING WAN INTERFACE
Display and Debug T1-F 
InterfacePerform the display command in all views to display the state of T1-F interface 
and other related information.
Ta b l e 163   Display and debug T1-F interface
CE3 InterfaceBoth E3 and E1 belong to ITU-T digital carrier system and are used in most areas 
outside the North America. The data transmission rate of E3 interface is 
34.368Mbps, and the line coding/decoding is HDB3 (High-Density Bipolar 3). 
CE3 interface has two...