Practice Lab Reflections #7

Gatekeeper

• Make sure gatekeepers setup to route according to the full E.164 number.
• You must have more than a zone match in order route the call.
• # is good for gatekeeper routing because there is no chance of overlap.
• The advantage of the default technology is that you don’t need to prepend the Tech-Prefix in the Called #.  The gatekeeper routes the call to the destination zone as defined by the matching zone prefix.  The gatekeeper will randomly choose a gateway in the destination zone that has registered with the default tech-prefix: gw-type-prefix 1#* default-technology

Gateway

• H.323 gateways view the + character as an invalid character.  You must do a number translation on the IOS gateway itself to re-add the + to the outbound calling party (ANI) number.
• Useful command for voice translation rules: “test voice translation-rule [rule#] [test#]”
  If you add a voice translation to the voice-port instead of the dial-peer, this will change all PSTN calls coming in/out of the T1/E1.
• When configuring a gateway and gatekeeper in CUCM that coincidentally happens to be the same device, remember that you cannot use the same IP address.  Either use a different physical interface or create a loopback address to use for the second logical device in CUCM.
• The following command is useful when configuring redundant dial peers to external H.323 endpoints.  It allows for timeouts and resulting failover capabilities:
  voice class h323 1
  h225 timeout tcp establish 3
• The following command is used to change the H.225 listen port:
  h323
  h225 listen-port 1820
• As a best practice, strip the 9 at the IOS gateway level to accommodate SRST capabilities.
• In order to strip the caller ID name information on an IOS gateway, use the “clid strip name” in dial-peer config mode.
• dsp-farm profiles are in a “shutdown” state by default.  Remember to “no shutdown” them.
• With H.323 gateways and SRST, it is always best to take the incoming calling number and manipulate it for call processing while the call is still within the IOS gateway.

CUCM

• Significant digits are always the right-most digits.
• H.323 Fast Start sends H.225 call control and H.245 call capabilities information over the same TCP 1720 port at the same time.  This allows for faster call establishment.
• Calling/Called Party Transformation Patterns should be completely separated from the call routing partitions.
  pt-ani-gw-hq
  css-ani-gw-hq
• SIP devices do not support the annunciator in CUCM.
• It is the destination device (from CUCM’s perspective) that determined the called/calling party transformations used.
  Local:         \+1212.XXXXXXX
  Long Distance:     \+1.!
  International:     \+.!
• With SIP dial rules in CUCM, the following commands are useful:
  >#    Used at the end of a string to bypass the interdigit timeout
  \*     Used at the beginning of a string to denote a number beginning with *
• Inbound globalization takes place after the call has been passed from the IOS gateway to CUCM.
• SIP does not offer an indication of the numbering type. Therefore, SIP gateways will not be able to receive an indication of the called or calling party number type set by CUCM
• When you uncheck “Use Device Pool Calling/Called Party Transformation CSS” on an MGCP gateway, you must bounce MGCP on the IOS itself.
• TIP: Whenever something fails, immediately restart the gateway or trunk in CUCM.  You never know.
• Remember to set “Stop Routing on Unallocated Number Flag” to FALSE.  This is required to allow failover across trunks in CUCM.
• No MTP check box is required when setting up interoperability between Cisco devices.  The devices use proprietary communication channels to enable MTP as necessary.
• Translation patterns preempt route patterns.
• The # is stripped by default when sending the call out of CUCM.  There is a service parameter to modify the way it behaves.
• When deploying site codes in a variable-length on-net dial plan, configure a translation pattern per site to translate 1XXX into 8-408-1XXX to be routed on via the PT-INTERNAL partition.
• When using the line device approach, remember the priority order is reversed for CTI devices.  For these devices, partitions in the device calling search space are given priority over those before the line casing search space.
• When using the line/device approach, make sure that the globalized version of the numbers are also blocked.  This is a gotcha.
• When using the line/device approach for extension mobility, the users must adapt their dialing behavior to that of the local site.
• The Call Forward All CSS under the line configuration is not concatenated with any other calling search space.  In order to function properly, they must be manually set.