https://community.cisco.com/t5/ip-telephony-and-phones/e1-port-cabling/m-p/3934576#M382917 <P>If the link flaps you can enable Debug isdn q921 on your router and check if there are any errors relating to cabling issue.</P><P>&nbsp;</P> Thu, 03 Oct 2019 12:17:22 GMT inderpreetsingh23 2019-10-03T12:17:22Z https://community.cisco.com/t5/ip-telephony-and-phones/e1-port-cabling/m-p/3934511#M382911 <P>We have a newly activated E1 port which flaps frequently in 3-4 days where layer 1 goes down and up. Its a 4351 cisco router. What type of cable you need to connected to E1 port ? RJ45 or RJ 48 ? CAT6 or CAT7 ? Crossover or Straight or its specific for E1?&nbsp;</P> Thu, 03 Oct 2019 09:25:12 GMT https://community.cisco.com/t5/ip-telephony-and-phones/e1-port-cabling/m-p/3934511#M382911 agrawalanamika 2019-10-03T09:25:12Z https://community.cisco.com/t5/ip-telephony-and-phones/e1-port-cabling/m-p/3934557#M382915 <P>Hello</P><P>&nbsp;</P><P>Here you find a good documentation regarding E1 cabling: <A href="https://www.ip-sa.pl/doc/ras/max800-6000/m6hwinst/cables.htm#18067" target="_blank">https://www.ip-sa.pl/doc/ras/max800-6000/m6hwinst/cables.htm#18067</A></P><P>&nbsp;</P><P>Hope this helps</P><P>Peter</P> Thu, 03 Oct 2019 11:50:58 GMT https://community.cisco.com/t5/ip-telephony-and-phones/e1-port-cabling/m-p/3934557#M382915 pwenger 2019-10-03T11:50:58Z https://community.cisco.com/t5/ip-telephony-and-phones/e1-port-cabling/m-p/3934576#M382917 <P>If the link flaps you can enable Debug isdn q921 on your router and check if there are any errors relating to cabling issue.</P><P>&nbsp;</P> Thu, 03 Oct 2019 12:17:22 GMT https://community.cisco.com/t5/ip-telephony-and-phones/e1-port-cabling/m-p/3934576#M382917 inderpreetsingh23 2019-10-03T12:17:22Z