<div dir="ltr">Morning Folks,<div><br clear="all"><div><p style="margin:0in;font-family:Calibri;font-size:11pt">We have implemented
a new SIP solution with Level 3 and found that we have outbound calling
failover issues. When a CUBE loses its ability to talk to its Level 3 Peer, but
can still talk to CUCM outbound calls will still connect to the CUBE, but fail
connecting to Level 3. In turn CUCM still thinks the call is connected since
the CUCM SIP trunk remains up to the CUBE.</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">Architecture Notes:</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">4 Locations with 1
CUBE Each</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">4 CUCM SIP Trunks
with each connecting to one of the 4 CUBEs</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">4 CUCM Route Groups
with Various CUBE/SIP Trunks assigned a Distribution Algorithm of <span style="font-style:italic">Top Down</span></p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">Each CUBE has 2 SIP
Peers</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">Each CUBE can only
talk to its respective SIP peer via its local Level 3 Transport to reduce call
control latency by not allowing it to use the DMVPN backup network</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">Level 3 does not
support SIP Options Ping</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">CUCM Trunks have SIP
Options Ping enabled</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">Call Flows:</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 0.375in;font-family:Calibri;font-size:11pt">Working
Flow:</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 0.375in;font-family:Calibri;font-size:11pt">Phone
----> SLRG ----> Route Group Member #1 ----> CUBE SIP TRUNK ---->
CUBE ----> Level 3 Transport ----> Level 3 SIP Peer #1/#2 ----> Call
Completes</p>
<p style="margin:0in 0in 0in 3.75in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 3.75in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 0.375in;font-family:Calibri;font-size:11pt">CUBE
Failure:</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 0.375in;font-family:Calibri;font-size:11pt">Phone
----> SLRG ----></p>
<p style="margin:0in 0in 0in 1.125in;font-family:Calibri;font-size:11pt"> Route Group Member #1 ----> CUBE
SIP TRUNK --X--> CUBE (CUCM Cant Reach CUBE)</p>
<p style="margin:0in 0in 0in 1.875in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 1.125in;font-family:Calibri;font-size:11pt"> CUCM Routes Call to Next Route Group
Member</p>
<p style="margin:0in 0in 0in 1.875in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 0.375in;font-family:Calibri;font-size:11pt"> Route Group
Member #2 ----> CUBE SIP TRUNK ----> CUBE ----> Level 3 Transport
----> Level 3 SIP Peer #1/#2 ----> Call Completes</p>
<p style="margin:0in 0in 0in 0.375in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 0.375in;font-family:Calibri;font-size:11pt">Level
3 Transport Failure/SIP Server Failure:</p>
<p style="margin:0in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 0.375in;font-family:Calibri;font-size:11pt">Phone
----> SLRG ----></p>
<p style="margin:0in 0in 0in 1.125in;font-family:Calibri;font-size:11pt"> Route Group Member #1 ----> CUBE
SIP TRUNK ----> CUBE --X--> Level 3 Transport (CUBE Cant Reach Level 3
SIP Server)</p>
<p style="margin:0in 0in 0in 1.875in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in 0in 0in 1.125in;font-family:Calibri;font-size:11pt"> CUCM Thinks Call Connects since the
CUBE accepts the call, Phone gets dead air, never tries the next RG Member</p>
<p style="margin:0in 0in 0in 1.875in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">My idea to fix this
is to use an IPSLA to ping the pingable address on the Level 3 SIP Servers. If
both address are unreachable then shutdown the CUCM Dial-Peers. This doesn’t
sounds like the best way of fixing it, but it should work. </p>
<p style="margin:0in;font-family:Calibri;font-size:11pt"> </p>
<p style="margin:0in;font-family:Calibri;font-size:11pt">If any has any other
better ideas please let me know.</p></div>-- <br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature">Erik Anderson</div></div><div class="gmail_signature" data-smartmail="gmail_signature">Telecom Manager</div><div class="gmail_signature" data-smartmail="gmail_signature">Some Random Corp.</div></div>