3Com Router 5000 and Router 6000 Family Release Notes v2.41 • Page 11
• On an ISDN interface, the Line Protocol state is up when no cable is attached to the port on
the interface. It is best to observe the interface’s Current State. The Current State will be
down if no cable is attached to the interface even though the Line Protocol will show it as
up.
• A Frame Relay sub-interface that has been configured as “Down” transmits packets.
• Displaying a Fractional E1 interface displays a Frame Format equal to NONE. The actual
Frame Format is no-crc.
• Frame Relay Payload Compression is displayed for PVC even after it is removed. Reset the
interface to resolve.
• Display interface for an ATM interface with sub-interfaces will display the same cumulative
statistical information - no individual statistics are provided; Instead use, display atm
interface to show more individualized statistics.
• An ATM PVC that is set with rate limiting and is heavily oversubscribed with data, will fail to
pass traffic. Other PVCs continue to work on the link.
• Changing the speed on a modem interface resets the interface. Do not change the modem
interface speed while a dialup session is active.
• The activity LED on the T3 ATM Module indicates heavy activity regardless of the amount of
traffic passing through it.
• Regardless of actual traffic running or not, T3 and E3 activity LEDs blink constantly.
3.5 Link Layer Protocol
• A frame relay link will not come up if the IP Address is changed, because the fr inarp table is
not refreshed. The user must reset the fr inarp table manually.
• Alarm-threshold values are not configurable when a T1-line is configured within a T3 link.
• Level-4 alarm-threshold is not supported for T1 links setup for SF frame format. The CLI will
not report an error.
• ATM AIS/RDI statistics are inaccurate.
• ATM OAM Segment Loop cells are not supported.
• Frame Relay PVCs can be modified when they are part of a PVC switching endpoint. Verify
first that the interface is not a PVC endpoint before making any changes, else traffic may be
disrupted.
• There is no DEBUG support for Multilink Fragmentation (FRF.16.1).
• Status and statistics for Multilink Fragmentation (FRF.16.1) cannot be viewed
• There is no support for ISDN switch type AT&T for BRI U interfaces. The router Command
Line Interface and the documentation specifically states that AT&T is only supported on PRI
interfaces. The default isdn protocol-type dss1 will connect to switches using AT&T switch
type on a BRI interface. This was tested with Lucent 5E, otherwise known as AT&T 5ess.
• Bridge-set traffic cannot be routed even though a bridge-set can be configured with an IP
address.
• FRF.9 Compression is still displayed upon viewing of PVC statistics, after the PVC is re-
mapped without FRF.9. After re-mapping a PVC to exclude FRF.9 compression, reset the
interface in order to clear any reference to FRF.9