Symptom

Version: U1980 V100R001C01SPC800

Network: PSTN–(PRA)–U1980

Symptom:

There is an intra-office SIP user whose sipue is 888, dn is 888, and long number is 88820888.

The office has the following related prefixes:

• Intra-office prefix 8: Both the minimum and maximum number lengths are 3, and no number change is configured.
• Intra-office prefix 88820: The minimum number length is 3, the maximum number lengths are 8, and the number change rule is to delete the first five digits from the called number. For example, when an outer-office user dials 88820888, the first five digits are deleted from the called number, and the called number after change is 888.

When an outer-office user dials 88820888, the call can be connected properly. When an intra-office user dials 888, an announcement is played indicating that the dialed number is incorrect. Based on the packet capture using the UCMaint, it is found that the cause is 156 indicating that the number format is invalid.

Routing based on the number length is configured and tested, but fails to take effect.

config add predeal index 7 changetype delete changepos 0 changelen 3

config add predeal index 6 changetype insertbynumlen numlen 3 changepos 0 newdn 111

config add predeal index 8 changetype insertbynumlen numlen 29 changepos 0 newdn 222

config add prefix dn 888 callcategory basic callattribute routelen cldpredeal yes cldindex 6&8 waitnextnumberlen 2000

config add prefix dn 111888 call basic call inter cldpredeal yes cldindex 7 min 3 max 6

config add prefix dn 222888 call basic call inter cldpredeal yes cldindex 7 min 8 max 11

Possible Cause

Prefix 88820 contains prefix 888. The prefix for routing based on the number length is not analyzed due to prefix conflict. As a result, number analysis fails.

Solution

1. Check the script for routing based on the number length. The script is correct.
2. Run the show prefix command to obtain all prefixes starting with 8. It is found that prefixes 8, 888, and 88820 exist.
3. Delete prefix 88820. The fault is rectified.

Conclusion and Suggestion

When an intra-office user dials 888, the call fails because prefix 88820 contains prefix 888. When the intra-office user dials 888, the U1980 matches the dialed number with prefix 88820, and waits for the next digit. If the fourth digit is not 2, the U1980 matches the dialed number with prefix 888. If the fourth digit is 2 but the fifth digit is not 0, the U1980 also matches the dialed number with prefix 888. Since the user dials only 888, the U1980 matches the number with prefix 88820 and does not perform further analysis. As a result, the call fails. When prefix conflict occurs and must be solved by routing based on the number length, delete the prefix that contains other prefixes. In this example, services run properly when prefix 88820 is deleted.